{
 "paper": {
  "school": "Nan Hua",
  "year": 2023,
  "level": "P4",
  "label": "Weighted Assessment",
  "source_prefix": "Nan Hua 2023 P4 Weighted Assessment",
  "has_answer_key": true,
  "notes": "Single PDF bundles three separate papers: Term 1 WA1 (Q1-14, pp.1-8), Term 2 WA2 (Q1-14, pp.9-18), Term 3 WA3 (Q1-14, pp.19-25). Combined answer key on pp.27-29. Each term restarts at Q1, so question sources are tagged WA1/WA2/WA3 to stay unique. All answers cross-checked against the key."
 },
 "questions": [
  {
   "n": 1,
   "type_id": 1,
   "question": "Which of the following is seventy thousand, three hundred and forty in numerals?",
   "answer0": "70 034",
   "answer1": "70 304",
   "answer2": "70 340",
   "answer3": "73 400",
   "correct_answer": 2,
   "skill_id": 105,
   "difficulty_id": 1,
   "explanation": "70 000 + 300 + 40 = 70 340. Option (3).",
   "hints": [
    "Seventy thousand = 70 000.",
    "Three hundred = 300, forty = 40. Add them: 70 000 + 300 + 40."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q1",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q1 = 3 (option index 2)."
  },
  {
   "n": 2,
   "type_id": 1,
   "question": "Arrange the following numbers from the largest to the smallest.<br>42 182 , 42 281 , 41 822",
   "answer0": "42 281 , 41 822 , 42 182",
   "answer1": "42 281 , 42 182 , 41 822",
   "answer2": "41 822 , 42 182 , 42 281",
   "answer3": "41 822 , 42 281 , 42 182",
   "correct_answer": 1,
   "skill_id": 107,
   "difficulty_id": 1,
   "explanation": "Largest to smallest: 42 281 > 42 182 > 41 822. Option (2).",
   "hints": [
    "Compare the thousands and hundreds digits.",
    "42 281 has the largest hundreds; 41 822 is smallest."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q2",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q2 = 2 (option index 1). Options (1)/(2) print same first term in PDF OCR; option 2 is the correct descending order."
  },
  {
   "n": 3,
   "type_id": 1,
   "question": "In the following number pattern, what is the missing number?<br>21 978, _______ , 21 778, 21 678, 21 578",
   "answer0": "22 178",
   "answer1": "22 078",
   "answer2": "21 968",
   "answer3": "21 878",
   "correct_answer": 3,
   "skill_id": 108,
   "difficulty_id": 1,
   "explanation": "The pattern decreases by 100 each term: 21 978 - 100 = 21 878. Option (4).",
   "hints": [
    "Find the difference between consecutive given terms.",
    "21 778 - 21 678 = 100, so subtract 100 from 21 978."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q3",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q3 = 4 (option index 3)."
  },
  {
   "n": 4,
   "type_id": 1,
   "question": "Which of the following numbers when rounded to the nearest hundred becomes 49 000?",
   "answer0": "48 875",
   "answer1": "48 965",
   "answer2": "49 099",
   "answer3": "49 144",
   "correct_answer": 1,
   "skill_id": 109,
   "difficulty_id": 2,
   "explanation": "Round to nearest hundred: 48 965 rounds to 49 000 (tens digit 6 rounds up). 48 875 to 48 900; 49 099 to 49 100; 49 144 to 49 100. Option (2).",
   "hints": [
    "Look at the tens digit to decide rounding to the nearest hundred.",
    "48 965: 965 rounds to 1000, giving 49 000."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q4",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q4 = 2 (option index 1)."
  },
  {
   "n": 5,
   "type_id": 1,
   "question": "Which of the following is a factor of both 12 and 28?",
   "answer0": "7",
   "answer1": "6",
   "answer2": "5",
   "answer3": "4",
   "correct_answer": 3,
   "skill_id": 113,
   "difficulty_id": 2,
   "explanation": "Factors of 12: 1,2,3,4,6,12. Factors of 28: 1,2,4,7,14,28. Common factor among options: 4. Option (4).",
   "hints": [
    "List the factors of 12 and of 28.",
    "Find a number that divides both exactly; 4 divides both."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q5",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q5 = 4 (option index 3)."
  },
  {
   "n": 6,
   "type_id": 1,
   "question": "Which of the following is a multiple of both 4 and 6?",
   "answer0": "10",
   "answer1": "12",
   "answer2": "16",
   "answer3": "18",
   "correct_answer": 1,
   "skill_id": 115,
   "difficulty_id": 2,
   "explanation": "Common multiples of 4 and 6 are multiples of 12. Among options, 12 is a multiple of both 4 and 6. Option (2).",
   "hints": [
    "A number must be in both the 4 times table and the 6 times table.",
    "The smallest common multiple of 4 and 6 is 12."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q6",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q6 = 2 (option index 1)."
  },
  {
   "n": 7,
   "type_id": 1,
   "question": "Peter stored 3425 boxes of masks in the warehouse. He sold 625 boxes of masks on Monday and 2150 boxes of masks on Tuesday. How many boxes of masks is he left with?",
   "answer0": "2800",
   "answer1": "2775",
   "answer2": "1275",
   "answer3": "650",
   "correct_answer": 3,
   "skill_id": 118,
   "difficulty_id": 2,
   "explanation": "3425 - 625 - 2150 = 3425 - 2775 = 650. Option (4).",
   "hints": [
    "Add the boxes sold: 625 + 2150 = 2775.",
    "Subtract from the start: 3425 - 2775 = 650."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q7",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q7 = 4 (option index 3)."
  },
  {
   "n": 8,
   "type_id": 1,
   "question": "The sum of two numbers is 75. One of the numbers is a multiple of 8. The other number is a factor of 21. What is the difference between the 2 numbers?",
   "answer0": "72",
   "answer1": "69",
   "answer2": "54",
   "answer3": "46",
   "correct_answer": 1,
   "skill_id": 118,
   "difficulty_id": 3,
   "explanation": "Factors of 21: 1, 3, 7, 21. The multiple of 8 = 75 - factor. 75 - 3 = 72 (a multiple of 8). So the numbers are 72 and 3; difference = 72 - 3 = 69. Option (2).",
   "hints": [
    "List factors of 21 and test which makes the other number a multiple of 8.",
    "75 - 3 = 72, and 72 = 8 x 9. Difference = 72 - 3."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q8",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q8 = 2 (option index 1)."
  },
  {
   "n": 9,
   "type_id": 2,
   "question": "A number is 5800 when rounded to the nearest hundred. What are the smallest and greatest possible numbers?<br>Smallest: [?]<br>Greatest: [?]",
   "answer0": "5750",
   "answer1": "5849",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 109,
   "difficulty_id": 2,
   "explanation": "Smallest rounding up to 5800: 5750 (5750 rounds to 5800). Greatest rounding down to 5800: 5849 (5849 rounds to 5800, 5850 rounds to 5900). Smallest = 5750, Greatest = 5849.",
   "hints": [
    "The smallest number rounding to 5800 is half-way down: 5750.",
    "The greatest is just below the next half-way point: 5849."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q9",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q9a = 5750, Q9b = 5849."
  },
  {
   "n": 10,
   "type_id": 2,
   "question": "There are 2400 red and blue stickers in a shop. The number of red stickers is three times as many as the number of blue stickers. How many blue stickers are there?<br>[?]",
   "answer0": "600",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 118,
   "difficulty_id": 2,
   "explanation": "Red is 3 times blue, so total = 4 units = 2400. 1 unit (blue) = 2400 / 4 = 600. Blue stickers = 600.",
   "hints": [
    "Blue = 1 unit, Red = 3 units, total = 4 units.",
    "4 units = 2400, so 1 unit = 2400 / 4."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q10",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q10: 4u = 2400, 1u = 600."
  },
  {
   "n": 11,
   "type_id": 2,
   "question": "Mr Tan bought 125 boxes of chocolates. Each box contained 28 chocolates. How many chocolates did Mr Tan buy in total?<br>[?]",
   "answer0": "3500",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 116,
   "difficulty_id": 2,
   "explanation": "125 x 28 = 3500 chocolates.",
   "hints": [
    "Multiply boxes by chocolates per box.",
    "125 x 28 = 125 x 28."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q11",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q11 = 3500."
  },
  {
   "n": 12,
   "type_id": 2,
   "question": "Mr Lim bought a bag of candies for his students. If he gives each student 6 candies, he will not have any candies left. If he gives each student 8 candies, he will be short of 6 candies. How many students did he have?<br>[?]",
   "answer0": "3",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 118,
   "difficulty_id": 3,
   "explanation": "Giving 8 instead of 6 needs 2 more per student, totalling a shortfall of 6 candies. Number of students = 6 / 2 = 3.",
   "hints": [
    "The extra needed per student is 8 - 6 = 2 candies.",
    "Total extra needed is the shortfall of 6, so students = 6 / 2."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q12",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q12 = 3."
  },
  {
   "n": 13,
   "type_id": 2,
   "question": "Three ovens and two printers cost $2300. A printer cost $80 more than an oven. What is the cost of an oven?<br>$[?]",
   "answer0": "428",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 118,
   "difficulty_id": 3,
   "explanation": "Replace 2 printers by ovens: each printer = oven + 80, so 2 printers = 2 ovens + 160. Total = 5 ovens + 160 = 2300, so 5 ovens = 2140, 1 oven = 2140 / 5 = $428.",
   "hints": [
    "2 printers cost 2 x $80 = $160 more than 2 ovens.",
    "5 ovens = 2300 - 160 = 2140, so 1 oven = 2140 / 5."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q13",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q13: 5u = 2300 - 160 = 2140; 1u = $428."
  },
  {
   "n": 14,
   "type_id": 2,
   "question": "John had twice as much money as Ken. After John spent $1064, Ken had four times as much money as John.<br>(a) How much money did John have in the end?<br>$[?]<br>(b) How much money did the both of them have at first?<br>$[?]",
   "answer0": "152",
   "answer1": "1824",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 118,
   "difficulty_id": 3,
   "explanation": "Ken's amount is unchanged. At first John = 2 x Ken. In the end Ken = 4 x John(end), so John(end) = Ken / 4. Let Ken = 1 unit; John(start) = 2 units; John(end) = Ken/4 = 1/4 unit. John spent $1064 = John(start) - John(end) = 2 - 1/4 = 7/4 units. So 7/4 units = 1064, 1 unit (1/4) ... using quarter-units: 7 quarter-units = 1064, 1 quarter-unit = 152, which is John(end) = $152. (b) At first John = 2 units = 8 quarter-units = 8 x 152 = $1216 and Ken = 4 quarter-units = $608; together = 12 quarter-units = 12 x $152 = $1824.",
   "hints": [
    "Ken's money never changes; express everything in quarter-units of Ken.",
    "John spent 7 quarter-units = $1064, so 1 quarter-unit (John's end amount) = $152; total at first = 12 quarter-units."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA1 Q14",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA1 Q14a: 7u = 1064, 1u = $152 (John's end amount). Q14b: 12u = 12 x $152 = $1824 (both at first)."
  },
  {
   "n": 15,
   "type_id": 1,
   "question": "$$3\\frac{2}{5}$$ = $$\\frac{[box]}{5}$$<br>What is the missing number in the box?",
   "answer0": "10",
   "answer1": "15",
   "answer2": "17",
   "answer3": "32",
   "correct_answer": 2,
   "skill_id": 119,
   "difficulty_id": 1,
   "explanation": "Convert mixed number to improper fraction: 3 x 5 + 2 = 17, so 3 2/5 = 17/5. Missing number = 17. Option (3).",
   "hints": [
    "Multiply the whole number by the denominator, then add the numerator.",
    "3 x 5 + 2 = 17."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q1",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "WA2 Term 2 paper, printed Q1. Answer key WA2 Q1 = 3 (option index 2). Stem shows 3 2/5 = box/5; box is the numerator blank."
  },
  {
   "n": 16,
   "type_id": 1,
   "question": "The figure is made up of identical triangles. What fraction of the figure is shaded?",
   "answer0": "$$\\frac{3}{4}$$",
   "answer1": "$$\\frac{3}{5}$$",
   "answer2": "$$\\frac{3}{8}$$",
   "answer3": "$$\\frac{5}{8}$$",
   "correct_answer": 3,
   "skill_id": 120,
   "difficulty_id": 2,
   "explanation": "The figure is divided into 8 identical triangles; 5 of them are shaded, giving 5/8. Option (4).",
   "hints": [
    "Count the total number of identical triangles.",
    "Count the shaded triangles and write shaded over total."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q2",
   "image_needed": true,
   "image_options": false,
   "image_file": "q16.png",
   "image_page": 10,
   "image_bbox": [
    0.37,
    0.18,
    0.55,
    0.34
   ],
   "image_loc": "upper-right area of the page beside options, rectangle made of shaded/unshaded triangles",
   "notes": "Answer key WA2 Q2 = 3 (option index 3 = 5/8). Figure required to count shaded triangles."
  },
  {
   "n": 17,
   "type_id": 1,
   "question": "In the number line, what is the mixed number represented by A?",
   "answer0": "$$2\\frac{7}{10}$$",
   "answer1": "$$2\\frac{7}{12}$$",
   "answer2": "$$3\\frac{2}{5}$$",
   "answer3": "$$3\\frac{2}{6}$$",
   "correct_answer": 2,
   "skill_id": 119,
   "difficulty_id": 2,
   "explanation": "The interval from 3 to 4 is divided into 5 equal parts; A is 2 parts past 3, so A = 3 2/5. Option (3).",
   "hints": [
    "Count how many equal parts each whole is split into between 3 and 4.",
    "A sits 2 small marks after 3."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q3",
   "image_needed": true,
   "image_options": false,
   "image_file": "q17.png",
   "image_page": 10,
   "image_bbox": [
    0.24,
    0.49,
    0.66,
    0.6
   ],
   "image_loc": "middle of page, horizontal number line from 2 to 4 with arrow marked A",
   "notes": "Answer key WA2 Q3 = 3 (option index 2 = 3 2/5). Number line figure required."
  },
  {
   "n": 18,
   "type_id": 1,
   "question": "Find the value of $$\\frac{7}{8}$$ - $$\\frac{1}{4}$$",
   "answer0": "$$\\frac{5}{8}$$",
   "answer1": "$$\\frac{6}{8}$$",
   "answer2": "$$1\\frac{1}{8}$$",
   "answer3": "$$1\\frac{1}{2}$$",
   "correct_answer": 0,
   "skill_id": 121,
   "difficulty_id": 2,
   "explanation": "1/4 = 2/8, so 7/8 - 2/8 = 5/8. Option (1).",
   "hints": [
    "Make the denominators the same: 1/4 = 2/8.",
    "Subtract: 7/8 - 2/8."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q4",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA2 Q4 = 1 (option index 0)."
  },
  {
   "n": 19,
   "type_id": 1,
   "question": "Find the value of $$\\frac{1}{3}$$ + $$\\frac{2}{9}$$ + $$\\frac{7}{9}$$",
   "answer0": "$$1\\frac{1}{9}$$",
   "answer1": "$$1\\frac{2}{9}$$",
   "answer2": "$$1\\frac{1}{3}$$",
   "answer3": "$$1\\frac{2}{3}$$",
   "correct_answer": 2,
   "skill_id": 121,
   "difficulty_id": 2,
   "explanation": "1/3 = 3/9, so 3/9 + 2/9 + 7/9 = 12/9 = 1 3/9 = 1 1/3. Option (3).",
   "hints": [
    "Convert 1/3 to ninths: 1/3 = 3/9.",
    "Add all ninths: 3/9 + 2/9 + 7/9 = 12/9, then simplify."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q5",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA2 Q5 = 3 (option index 2)."
  },
  {
   "n": 20,
   "type_id": 1,
   "question": "What is the size of ∠XYZ?",
   "answer0": "78°",
   "answer1": "82°",
   "answer2": "102°",
   "answer3": "118°",
   "correct_answer": 1,
   "skill_id": 140,
   "difficulty_id": 2,
   "explanation": "Reading the protractor where ray YZ is along the 0 line and ray YX, angle XYZ measures 82 degrees. Option (2).",
   "hints": [
    "Start from 0 on the side along YZ and read up to ray YX.",
    "Use the inner scale that starts at 0 on YZ."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q6",
   "image_needed": true,
   "image_options": false,
   "image_file": "q20.png",
   "image_page": 12,
   "image_bbox": [
    0.16,
    0.16,
    0.66,
    0.36
   ],
   "image_loc": "upper portion of page, semicircular protractor with rays labelled X, Y, Z",
   "notes": "Answer key WA2 Q6 = 2 (option index 1 = 82 degrees). Protractor figure required."
  },
  {
   "n": 21,
   "type_id": 1,
   "question": "Arrange the following fractions from the smallest to the greatest.<br>$$1\\frac{1}{4}$$ , $$\\frac{12}{11}$$ , $$1\\frac{1}{8}$$",
   "answer0": "$$1\\frac{1}{4}$$ , $$1\\frac{1}{8}$$ , $$\\frac{12}{11}$$",
   "answer1": "$$1\\frac{1}{8}$$ , $$\\frac{12}{11}$$ , $$1\\frac{1}{4}$$",
   "answer2": "$$\\frac{12}{11}$$ , $$1\\frac{1}{4}$$ , $$1\\frac{1}{8}$$",
   "answer3": "$$\\frac{12}{11}$$ , $$1\\frac{1}{8}$$ , $$1\\frac{1}{4}$$",
   "correct_answer": 3,
   "skill_id": 119,
   "difficulty_id": 3,
   "explanation": "12/11 = 1 1/11. Compare 1/11, 1/8, 1/4: 1/11 < 1/8 < 1/4. So smallest to greatest: 12/11, 1 1/8, 1 1/4. Option (4).",
   "hints": [
    "Write 12/11 as a mixed number: 1 1/11.",
    "All are 1 plus a fraction; compare 1/11, 1/8, 1/4 (smaller denominator = larger)."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q7",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA2 Q7 = 4 (option index 3)."
  },
  {
   "n": 22,
   "type_id": 1,
   "question": "Jane had 6 cakes. She gave $$\\frac{1}{2}$$ of a cake to her sister and $$\\frac{1}{3}$$ of a cake to her brother. How many cakes had she left?",
   "answer0": "$$\\frac{2}{5}$$",
   "answer1": "$$\\frac{5}{6}$$",
   "answer2": "$$5\\frac{1}{6}$$",
   "answer3": "$$5\\frac{3}{5}$$",
   "correct_answer": 2,
   "skill_id": 122,
   "difficulty_id": 2,
   "explanation": "Given away: 1/2 + 1/3 = 3/6 + 2/6 = 5/6 of a cake. Left: 6 - 5/6 = 5 1/6 cakes. Option (3).",
   "hints": [
    "Add the two fractions given away: 1/2 + 1/3.",
    "Subtract that total from 6 whole cakes."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q8",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA2 Q8 = 3 (option index 2 = 5 1/6)."
  },
  {
   "n": 23,
   "type_id": 2,
   "question": "ABCD is a rectangle. ∠DBC = 70°. AB = 8 cm, AD = 2 cm.<br>(a) Find the length of DC.<br>[?] cm<br>(b) Find ∠ABD.<br>[?]°",
   "answer0": "8",
   "answer1": "20",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 143,
   "difficulty_id": 2,
   "explanation": "(a) In a rectangle opposite sides are equal, so DC = AB = 8 cm. (b) Angle ABC is a right angle (90 degrees) in the rectangle; angle ABD = angle ABC - angle DBC = 90 - 70 = 20 degrees.",
   "hints": [
    "Opposite sides of a rectangle are equal in length.",
    "The corner angle ABC = 90 degrees; subtract angle DBC."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q9",
   "image_needed": true,
   "image_options": false,
   "image_file": "q23.png",
   "image_page": 14,
   "image_bbox": [
    0.16,
    0.24,
    0.62,
    0.42
   ],
   "image_loc": "upper-left of page, tilted rectangle ABCD with diagonal DB, marked 8 cm, 2 cm and 70 degrees",
   "notes": "Answer key WA2 Q9a = 8 cm, Q9b = 90 - 70 = 20 degrees. Rectangle figure with diagonal required."
  },
  {
   "n": 24,
   "type_id": 0,
   "question": "In the grid, draw and label the square ABCD. Lines AB and BC have been drawn for you.",
   "answer0": null,
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 143,
   "difficulty_id": 2,
   "explanation": "Complete the square by drawing sides CD and DA so that all four sides are equal and meet at right angles, with D positioned so ABCD forms a square on the grid.",
   "hints": [],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q10",
   "image_needed": true,
   "image_options": false,
   "image_file": "q24.png",
   "image_page": 15,
   "image_bbox": [
    0.28,
    0.16,
    0.72,
    0.46
   ],
   "image_loc": "upper-middle of page, square grid with partial lines AB and BC drawn, points A, B, C labelled",
   "notes": "type_id 0: interactive draw-on-grid task, no app question type. Answer (from key): complete square ABCD by drawing the remaining two sides; D is the fourth vertex. SKIPPED on insert."
  },
  {
   "n": 25,
   "type_id": 2,
   "question": "Emma has 24 apples and oranges. $$\\frac{3}{8}$$ of the fruits are apples. How many more oranges than apples does Emma have?<br>[?]",
   "answer0": "6",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 120,
   "difficulty_id": 2,
   "explanation": "Apples = 3/8 of 24 = 9. Oranges = 24 - 9 = 15. More oranges than apples = 15 - 9 = 6.",
   "hints": [
    "Find the number of apples: 3/8 of 24.",
    "Oranges = 24 - apples; then find the difference."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q11",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA2 Q11 prints '125 x 28 = 3500', which is an erroneous copy of WA1 Q11; the correct answer to this question is 6 (apples 9, oranges 15, difference 6)."
  },
  {
   "n": 26,
   "type_id": 1,
   "question": "Simon was standing at Point X. After making a 135° anticlockwise turn, he ended up facing the MRT Station. Where was he facing at first?",
   "answer0": "Cinema",
   "answer1": "Garden",
   "answer2": "Library",
   "answer3": "Swimming Complex",
   "correct_answer": 0,
   "skill_id": 141,
   "difficulty_id": 3,
   "explanation": "The 8 locations are spaced 45 degrees apart around X. A 135-degree anticlockwise turn = 3 steps anticlockwise. To end facing MRT Station, undo the turn by going 3 steps clockwise from MRT Station: MRT Station (SE) -> Swimming Complex (E) -> Shopping Mall (NE) -> Cinema (N). He first faced the Cinema. Option (1).",
   "hints": [
    "Each adjacent direction is 45 degrees apart; 135 degrees = 3 positions.",
    "Rotate back 3 positions clockwise from the MRT Station to find the start."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q12",
   "image_needed": true,
   "image_options": false,
   "image_file": "q26.png",
   "image_page": 16,
   "image_bbox": [
    0.14,
    0.17,
    0.74,
    0.42
   ],
   "image_loc": "upper portion of page, 8-point compass diagram centred on X with labelled locations plus a North arrow at right",
   "notes": "Converted to MCQ (original is open answer; key = 'Library'). NOTE: Re-deriving from the printed compass (Cinema N, Shopping Mall NE, Swimming Complex E, MRT SE, Carpark S, Park SW, Library W, Garden NW), a 135 deg anticlockwise turn ending at MRT means start = Cinema. The answer key states 'Library'; key may use a different turn convention. Marked correct_answer=0 (Cinema) per geometry; flag for human QA. 8-point compass figure required."
  },
  {
   "n": 27,
   "type_id": 2,
   "question": "Amy has $$\\frac{3}{5}$$ kg of sugar. Bala has $$\\frac{1}{3}$$ kg of sugar more than Amy.<br>(a) How much sugar does Bala have? Express your answer in its simplest form.<br>[?] kg<br>(b) How much sugar do they have altogether? Express your answer in its simplest form.<br>[?] kg",
   "answer0": "14/15",
   "answer1": "1 8/15",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 122,
   "difficulty_id": 2,
   "explanation": "(a) Bala = 3/5 + 1/3 = 9/15 + 5/15 = 14/15 kg. (b) Altogether = Amy + Bala = 3/5 + 14/15 = 9/15 + 14/15 = 23/15 = 1 8/15 kg.",
   "hints": [
    "Use a common denominator of 15 for fifths and thirds.",
    "Bala = 3/5 + 1/3; total = Amy + Bala."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q13",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA2 Q13a = 14/15 kg, Q13b = 1 8/15 kg. FIB fraction answers kept plain (14/15, 1 8/15)."
  },
  {
   "n": 28,
   "type_id": 2,
   "question": "$$\\frac{1}{3}$$ of a bottle was filled with orange juice. After John poured in another 600 ml of orange juice, it became $$\\frac{5}{9}$$ full. How much orange juice can the bottle hold when it is completely full? Give your answer in millilitres.<br>[?] ml",
   "answer0": "2700",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 122,
   "difficulty_id": 3,
   "explanation": "Increase in fraction filled = 5/9 - 1/3 = 5/9 - 3/9 = 2/9. This equals 600 ml, so 2 units = 600 ml, 1 unit (1/9) = 300 ml. Full bottle = 9 units = 9 x 300 = 2700 ml.",
   "hints": [
    "Find the fraction added: 5/9 - 1/3.",
    "That fraction equals 600 ml; scale up to the full 9/9."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA2 Q14",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA2 Q14: 2u = 600, 1u = 300, 9u = 2700 ml."
  },
  {
   "n": 29,
   "type_id": 1,
   "question": "Arrange the following decimals in decreasing order.<br>7.051 , 7.101 , 7.011 , 7.105",
   "answer0": "7.011 , 7.051 , 7.101 , 7.105",
   "answer1": "7.011 , 7.105 , 7.051 , 7.101",
   "answer2": "7.105 , 7.011 , 7.101 , 7.051",
   "answer3": "7.105 , 7.101 , 7.051 , 7.011",
   "correct_answer": 3,
   "skill_id": 124,
   "difficulty_id": 2,
   "explanation": "Decreasing (greatest to smallest): 7.105 > 7.101 > 7.051 > 7.011. Option (4).",
   "hints": [
    "Compare the tenths, then hundredths, then thousandths.",
    "Largest first: 7.105, then 7.101, 7.051, 7.011."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q1",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "WA3 Term 3 paper, printed Q1. Answer key WA3 Q1 = 4 (option index 3)."
  },
  {
   "n": 30,
   "type_id": 1,
   "question": "Round 38.695 to the nearest tenth.",
   "answer0": "38.0",
   "answer1": "38.6",
   "answer2": "38.7",
   "answer3": "39.0",
   "correct_answer": 2,
   "skill_id": 128,
   "difficulty_id": 2,
   "explanation": "Nearest tenth: look at the hundredths digit (9). 38.695 rounds up to 38.7. Option (3).",
   "hints": [
    "The tenths digit is 6; check the hundredths digit (9) to round.",
    "9 rounds the tenths up: 38.6 becomes 38.7."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q2",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q2 = 3 (option index 2)."
  },
  {
   "n": 31,
   "type_id": 1,
   "question": "Express $$5\\frac{9}{25}$$ as a decimal.",
   "answer0": "5.09",
   "answer1": "5.25",
   "answer2": "5.36",
   "answer3": "5.90",
   "correct_answer": 2,
   "skill_id": 127,
   "difficulty_id": 2,
   "explanation": "9/25 = 36/100 = 0.36, so 5 9/25 = 5.36. Option (3).",
   "hints": [
    "Make the denominator 100: 9/25 = 36/100.",
    "36/100 = 0.36, add to the whole number 5."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q3",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q3 = 3 (option index 2)."
  },
  {
   "n": 32,
   "type_id": 1,
   "question": "Express 2.003 as a fraction.",
   "answer0": "$$2\\frac{1}{3}$$",
   "answer1": "$$2\\frac{3}{10}$$",
   "answer2": "$$2\\frac{3}{100}$$",
   "answer3": "$$2\\frac{3}{1000}$$",
   "correct_answer": 3,
   "skill_id": 126,
   "difficulty_id": 2,
   "explanation": "0.003 = 3 thousandths = 3/1000, so 2.003 = 2 3/1000. Option (4).",
   "hints": [
    "The last digit is in the thousandths place.",
    "0.003 = 3/1000."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q4",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q4 = 4 (option index 3)."
  },
  {
   "n": 33,
   "type_id": 1,
   "question": "What is the missing number in the box?<br>8.175 = 8 + 0.1 + [box] + 0.005",
   "answer0": "0.007",
   "answer1": "0.07",
   "answer2": "0.7",
   "answer3": "7",
   "correct_answer": 1,
   "skill_id": 123,
   "difficulty_id": 2,
   "explanation": "8.175 = 8 + 0.1 + 0.07 + 0.005. The hundredths value is 0.07. Option (2).",
   "hints": [
    "Break 8.175 into place values: 8, 0.1, 0.07, 0.005.",
    "The missing part is the hundredths: 0.07."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q5",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q5 = 2 (option index 1)."
  },
  {
   "n": 34,
   "type_id": 1,
   "question": "3.46 is 0.1 more than _______.",
   "answer0": "3.36",
   "answer1": "3.45",
   "answer2": "3.47",
   "answer3": "3.56",
   "correct_answer": 0,
   "skill_id": 129,
   "difficulty_id": 1,
   "explanation": "3.46 - 0.1 = 3.36. Option (1).",
   "hints": [
    "If 3.46 is 0.1 more, subtract 0.1.",
    "3.46 - 0.10 = 3.36."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q6",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q6 = 1 (option index 0)."
  },
  {
   "n": 35,
   "type_id": 1,
   "question": "A pen cost $2.60. Diana bought two pens and gave the cashier $10. How much change did she get?",
   "answer0": "$4.80",
   "answer1": "$5.20",
   "answer2": "$7.40",
   "answer3": "$12.60",
   "correct_answer": 0,
   "skill_id": 131,
   "difficulty_id": 2,
   "explanation": "Two pens = 2 x $2.60 = $5.20. Change = $10 - $5.20 = $4.80. Option (1).",
   "hints": [
    "Find the cost of two pens: 2 x $2.60.",
    "Subtract from $10."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q7",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q7 = 1 (option index 0)."
  },
  {
   "n": 36,
   "type_id": 1,
   "question": "The total length of one yellow ribbon and one green ribbon is 8.7 m. Each yellow ribbon is twice as long as the green ribbon. What is the length of the yellow ribbon?",
   "answer0": "1.45 m",
   "answer1": "2.90 m",
   "answer2": "4.35 m",
   "answer3": "5.80 m",
   "correct_answer": 3,
   "skill_id": 131,
   "difficulty_id": 2,
   "explanation": "Yellow = 2 units, green = 1 unit, total = 3 units = 8.7 m. 1 unit = 2.9 m. Yellow = 2 x 2.9 = 5.80 m. Option (4).",
   "hints": [
    "Green = 1 unit, yellow = 2 units, total 3 units = 8.7 m.",
    "1 unit = 8.7 / 3 = 2.9 m; yellow = 2 units."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q8",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q8 = 4 (option index 3)."
  },
  {
   "n": 37,
   "type_id": 2,
   "question": "Find the length of the rectangle given its perimeter. Perimeter = 42 cm, width = 6 cm.<br>[?] cm",
   "answer0": "15",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 136,
   "difficulty_id": 2,
   "explanation": "Perimeter = 2 x (length + width). 42 / 2 = 21 = length + width. Length = 21 - 6 = 15 cm.",
   "hints": [
    "Half the perimeter = length + width.",
    "42 / 2 = 21, then subtract the width 6."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q9",
   "image_needed": true,
   "image_options": false,
   "image_file": "q37.png",
   "image_page": 22,
   "image_bbox": [
    0.18,
    0.25,
    0.5,
    0.38
   ],
   "image_loc": "upper-left, rectangle with top side marked '?', height 6 cm, label 'Perimeter = 42 cm' inside",
   "notes": "Answer key WA3 Q9: 42/2 = 21, 21 - 6 = 15 cm. Rectangle figure required."
  },
  {
   "n": 38,
   "type_id": 2,
   "question": "The area of the square is twice the area of the rectangle. The rectangle measures 9 cm by 2 cm. Find the length of one side of the square.<br>[?] cm",
   "answer0": "6",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 137,
   "difficulty_id": 2,
   "explanation": "Rectangle area = 9 x 2 = 18 cm2. Square area = 2 x 18 = 36 cm2. Side of square = sqrt(36) = 6 cm.",
   "hints": [
    "Find the rectangle's area, then double it for the square.",
    "Square area 36 = side x side, so side = 6 cm."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q10",
   "image_needed": true,
   "image_options": false,
   "image_file": "q38.png",
   "image_page": 22,
   "image_bbox": [
    0.26,
    0.58,
    0.78,
    0.74
   ],
   "image_loc": "middle of page, a square marked '?' on left and a long rectangle marked 9 cm by 2 cm on right",
   "notes": "Answer key WA3 Q10: 18 x 2 = 36, 6 x 6 = 36, side = 6 cm. Square + rectangle figure required."
  },
  {
   "n": 39,
   "type_id": 2,
   "question": "In a long jump competition, Aaron and Benson jumped the same distance while Caleb jumped 0.18 m more than Aaron. If the three boys jumped a total distance 4.56 m, how far did Aaron jump?<br>[?] m",
   "answer0": "1.46",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 131,
   "difficulty_id": 3,
   "explanation": "Subtract Caleb's extra: 4.56 - 0.18 = 4.38 m is 3 equal Aaron-jumps. Aaron = 4.38 / 3 = 1.46 m.",
   "hints": [
    "Remove Caleb's extra 0.18 m so all three equal Aaron's jump.",
    "4.56 - 0.18 = 4.38, then divide by 3."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q11",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q11: 4.56 - 0.18 = 4.38, 4.38 / 3 = 1.46 m."
  },
  {
   "n": 40,
   "type_id": 2,
   "question": "The price of apples sold in a shop is as follows:<br>One apple costs $0.90<br>A pack of five apples costs $3.75<br>Alice wants to buy 12 apples. What is the least amount of money she has to pay?<br>$[?]",
   "answer0": "9.30",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 131,
   "difficulty_id": 3,
   "explanation": "Buy 2 packs (10 apples) = 2 x $3.75 = $7.50, plus 2 single apples = 2 x $0.90 = $1.80. Total = $7.50 + $1.80 = $9.30. This is cheaper than other combinations.",
   "hints": [
    "Packs of 5 are cheaper per apple, so buy as many packs as possible.",
    "2 packs (10 apples) + 2 single apples = 12 apples."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q12",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q12: 3.75 x 2 = 7.5; 0.9 x 2 = 1.8; 1.8 + 7.5 = $9.30."
  },
  {
   "n": 41,
   "type_id": 2,
   "question": "A dress and five identical T-shirts cost $132.50. A dress and two of the identical T-shirts cost $75.80. What is the cost of one T-shirt?<br>$[?]",
   "answer0": "18.90",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 131,
   "difficulty_id": 3,
   "explanation": "Difference in T-shirts = 5 - 2 = 3, difference in cost = $132.50 - $75.80 = $56.70. One T-shirt = $56.70 / 3 = $18.90.",
   "hints": [
    "Subtract the two totals to remove the dress.",
    "The difference buys 3 T-shirts; divide by 3."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q13",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Answer key WA3 Q13: 5 - 2 = 3; 132.5 - 75.8 = 56.7; 56.7 / 3 = $18.90."
  },
  {
   "n": 42,
   "type_id": 2,
   "question": "Museum of Ice Cream entrance fees: Adult $28.90, Child (12 years old and below) $? . Weekend Family Package: Two adults $55, First two children $15.90 each, Additional child $12 each.<br>(a) Mrs Lim brought her two children under the age of 12 to the Museum of Ice Cream on Wednesday. She paid $61.90 in total. What is the entrance fee for a child under 12 years old?<br>$[?]<br>(b) Mr and Mrs Tan brought their three children under the age of 12 to the Museum of Ice Cream on Saturday. How much did they pay for the entrance tickets altogether?<br>$[?]",
   "answer0": "16.50",
   "answer1": "98.80",
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 131,
   "difficulty_id": 3,
   "explanation": "(a) Wednesday is a weekday so normal fees apply: 1 adult + 2 children = $61.90. Adult = $28.90, so 2 children = 61.90 - 28.90 = $33.00, one child = 33 / 2 = $16.50. (b) Saturday uses the Weekend Family Package: two adults $55, first two children 2 x $15.90 = $31.80, additional (third) child $12. Total = 55 + 31.80 + 12 = $98.80.",
   "hints": [
    "(a) Subtract the adult fee, then split the rest between 2 children.",
    "(b) Saturday = Weekend Family Package: $55 + 2 x $15.90 + $12."
   ],
   "source": "Nan Hua 2023 P4 Weighted Assessment WA3 Q14",
   "image_needed": true,
   "image_options": false,
   "image_file": "q42.png",
   "image_page": 25,
   "image_bbox": [
    0.14,
    0.14,
    0.86,
    0.3
   ],
   "image_loc": "top of page, 'Museum of Ice Cream' title with an entrance-fees table on the left and a starburst Weekend Family Package panel on the right",
   "notes": "Answer key WA3 Q14a: 61.9 - 28.9 = 33, 33 / 2 = $16.50. Q14b: 15.9 x 2 = 31.8, 31.8 + 12 (+55) = $98.80. Fees table/package figure helpful for context."
  }
 ]
}