{
"paper": {
"school": "Nan Hua",
"year": 2024,
"level": "P4",
"label": "Term 2 Review",
"source_prefix": "Nan Hua 2024 P4 Term 2 Review",
"has_answer_key": true
},
"questions": [
{
"n": 1,
"type_id": 1,
"question": "$$8\\frac{5}{9} = \\frac{[\\,\\,\\,]}{9}$$
What is the missing number in the box?",
"answer0": "13",
"answer1": "22",
"answer2": "72",
"answer3": "77",
"correct_answer": 3,
"skill_id": 119,
"difficulty_id": 1,
"explanation": "To convert the mixed number $$8\\frac{5}{9}$$ to an improper fraction, multiply the whole number by the denominator and add the numerator: $$8 \\times 9 + 5 = 72 + 5 = 77$$. So $$8\\frac{5}{9} = \\frac{77}{9}$$. The missing number is 77.",
"hints": ["An improper fraction over 9 equals the mixed number, so the numerator = whole number x 9 + the original numerator.", "Compute 8 x 9 + 5."],
"source": "Nan Hua 2024 P4 Term 2 Review Q1",
"image_needed": false,
"image_options": false,
"image_file": null,
"notes": "Key: option 4 (77)."
},
{
"n": 2,
"type_id": 1,
"question": "In the following figure, how many of the marked angles are obtuse?",
"answer0": "1",
"answer1": "2",
"answer2": "3",
"answer3": "4",
"correct_answer": 2,
"skill_id": 140,
"difficulty_id": 2,
"explanation": "An obtuse angle is greater than 90 degrees but less than 180 degrees. Examining each of the five marked angles in the figure, 3 of them open wider than a right angle (obtuse) while the others are acute. The answer is 3.",
"hints": ["An obtuse angle is bigger than a right angle (90 degrees) but smaller than a straight angle.", "Count only the marked angles that look wider than a square corner."],
"source": "Nan Hua 2024 P4 Term 2 Review Q2",
"image_needed": true,
"image_options": false,
"image_file": "q2.png",
"image_page": 2,
"image_bbox": [0.18, 0.50, 0.62, 0.69],
"image_loc": "polygon figure with marked angles, middle-left of page below the question",
"notes": "Key: option 3 (3 obtuse angles)."
},
{
"n": 3,
"type_id": 1,
"question": "Measure $$\\angle AOC$$.",
"answer0": "$$40^\\circ$$",
"answer1": "$$70^\\circ$$",
"answer2": "$$110^\\circ$$",
"answer3": "$$140^\\circ$$",
"correct_answer": 2,
"skill_id": 140,
"difficulty_id": 2,
"explanation": "Ray OA lies along the 0 degree mark of the protractor (the straight base line). Ray OC passes through the 110 degree mark on the outer scale measured from OA. Therefore $$\\angle AOC = 110^\\circ$$.",
"hints": ["Read the protractor scale starting from 0 along ray OA.", "Follow ray OC to where it crosses the scale."],
"source": "Nan Hua 2024 P4 Term 2 Review Q3",
"image_needed": true,
"image_options": false,
"image_file": "q3.png",
"image_page": 3,
"image_bbox": [0.16, 0.16, 0.86, 0.40],
"image_loc": "protractor with rays A, O, B, C, D near top of page",
"notes": "Key: option 3 (110 degrees)."
},
{
"n": 4,
"type_id": 1,
"question": "In the letters $$MATH\\ IS\\ FUN$$, how many letters have more than 2 right angles?",
"answer0": "1",
"answer1": "2",
"answer2": "3",
"answer3": "6",
"correct_answer": 1,
"skill_id": 139,
"difficulty_id": 2,
"explanation": "Count the right angles (square corners) formed in each block capital letter of MATH IS FUN. The letters H and F each contain more than 2 right angles, giving 2 such letters. The answer is 2.",
"hints": ["A right angle is a square corner (90 degrees).", "Look at each block letter and count its square corners; you need more than two."],
"source": "Nan Hua 2024 P4 Term 2 Review Q4",
"image_needed": true,
"image_options": false,
"image_file": "q4.png",
"image_page": 3,
"image_bbox": [0.10, 0.62, 0.62, 0.70],
"image_loc": "large block letters MATH IS FUN below the question",
"notes": "Key: option 2 (2 letters)."
},
{
"n": 5,
"type_id": 1,
"question": "Arrange the following fractions in increasing order.
$$\\frac{19}{6}\\quad 3\\frac{6}{7}\\quad \\frac{29}{9}$$",
"answer0": "$$3\\frac{6}{7},\\ \\frac{29}{9},\\ \\frac{19}{6}$$",
"answer1": "$$3\\frac{6}{7},\\ \\frac{19}{6},\\ \\frac{29}{9}$$",
"answer2": "$$\\frac{19}{6},\\ \\frac{29}{9},\\ 3\\frac{6}{7}$$",
"answer3": "$$\\frac{29}{9},\\ \\frac{19}{6},\\ 3\\frac{6}{7}$$",
"correct_answer": 2,
"skill_id": 124,
"difficulty_id": 3,
"explanation": "Convert each to a decimal to compare: $$\\frac{19}{6} \\approx 3.17$$, $$\\frac{29}{9} \\approx 3.22$$, $$3\\frac{6}{7} \\approx 3.86$$. In increasing order: $$\\frac{19}{6}, \\frac{29}{9}, 3\\frac{6}{7}$$. This is option 3.",
"hints": ["Convert each fraction to a decimal or a common form so you can compare sizes.", "Increasing order means smallest first."],
"source": "Nan Hua 2024 P4 Term 2 Review Q5",
"image_needed": false,
"image_options": false,
"image_file": null,
"notes": "Key: option 3. Fraction options so MCQ (no FIB)."
},
{
"n": 6,
"type_id": 1,
"question": "The table shows the number of Primary 4 students who can swim in a primary school. There are equal number of students in 4A, 4B and 4C.
Which of the following shows the correct data for (a) and (b)?",
"answer0": "(a) 6 , (b) 12",
"answer1": "(a) 20 , (b) 22",
"answer2": "(a) 20 , (b) 44",
"answer3": "(a) 22 , (b) 44",
"correct_answer": 1,
"skill_id": 147,
"difficulty_id": 3,
"explanation": "Class 4A total = 28 + 8 = 36 students. Each class has 36 students. For 4B: (a) = 36 - 16 = 20 cannot swim. For 4C: (b) = 36 - 14 = 22 can swim. So (a) = 20 and (b) = 22, which is option 2.",
"hints": ["Use 4A to find the class size: students who can swim + students who cannot swim.", "All three classes have the same total; subtract the known value in each class."],
"source": "Nan Hua 2024 P4 Term 2 Review Q6",
"image_needed": true,
"image_options": false,
"image_file": "q6.png",
"image_page": 4,
"image_bbox": [0.16, 0.54, 0.78, 0.67],
"image_loc": "table with columns 4A 4B 4C and rows can/cannot swim, middle of page",
"notes": "Key: option 2 (a=20, b=22)."
},
{
"n": 7,
"type_id": 0,
"question": "What are two other ways of naming $$\\angle b$$?",
"answer0": null,
"answer1": null,
"answer2": null,
"answer3": null,
"correct_answer": null,
"skill_id": 139,
"difficulty_id": 2,
"explanation": "Angle b is at vertex B, between ray BD and ray BC. Using three-letter naming with the vertex in the middle, it can be named $$\\angle DBC$$ or $$\\angle CBD$$.",
"hints": ["Name an angle with three letters putting the vertex in the middle.", "The two rays forming angle b are BD and BC."],
"source": "Nan Hua 2024 P4 Term 2 Review Q7",
"image_needed": true,
"image_options": false,
"image_file": "q7.png",
"image_page": 5,
"image_bbox": [0.18, 0.26, 0.66, 0.40],
"image_loc": "angle diagram with rays A-B-C and D, angles a and b at B",
"notes": "Two-answer naming task (angle DBC and CBD). No single value/sequence answer and grading by exact text match is fragile, so type_id 0. Key: (i) DBC (ii) CBD."
},
{
"n": 8,
"type_id": 0,
"question": "Draw the angle with the given line. Mark and label the angle.
$$\\angle RQS = 135^\\circ$$",
"answer0": null,
"answer1": null,
"answer2": null,
"answer3": null,
"correct_answer": null,
"skill_id": 140,
"difficulty_id": 2,
"explanation": "Place the protractor centre on Q with the base line along QR. Measure 135 degrees from ray QR and draw ray QS, then label the 135 degree angle RQS.",
"hints": ["Line up the protractor centre on the vertex Q and the base line on QR.", "Count to 135 degrees and draw the ray QS."],
"source": "Nan Hua 2024 P4 Term 2 Review Q8",
"image_needed": true,
"image_options": false,
"image_file": "q8.png",
"image_page": 5,
"image_bbox": [0.18, 0.62, 0.78, 0.82],
"image_loc": "protractor with base line P-Q-R, lower half of page",
"notes": "Drawing/construction task — no app value answer, so type_id 0 (skipped on insert). Key shows a drawn 135 degree angle."
},
{
"n": 9,
"type_id": 1,
"question": "Express $$\\frac{74}{8}$$ as a mixed number in its simplest form.",
"answer0": "$$9\\frac{1}{4}$$",
"answer1": "$$9\\frac{2}{8}$$",
"answer2": "$$9\\frac{1}{8}$$",
"answer3": "$$8\\frac{1}{4}$$",
"correct_answer": 0,
"skill_id": 119,
"difficulty_id": 2,
"explanation": "Divide: $$74 \\div 8 = 9$$ remainder $$2$$, so $$\\frac{74}{8} = 9\\frac{2}{8}$$. Simplify $$\\frac{2}{8} = \\frac{1}{4}$$. Therefore $$\\frac{74}{8} = 9\\frac{1}{4}$$.",
"hints": ["Divide the numerator by the denominator to find the whole number and remainder.", "Simplify the fractional part to its lowest terms."],
"source": "Nan Hua 2024 P4 Term 2 Review Q9",
"image_needed": false,
"image_options": false,
"image_file": null,
"notes": "Answer is a mixed number, so MCQ (not FIB). Key: 9 1/4."
},
{
"n": 10,
"type_id": 2,
"question": "What is the missing number in the box?
$$\\frac{6}{9} = \\frac{[?]}{15}$$",
"answer0": "10",
"answer1": null,
"answer2": null,
"answer3": null,
"correct_answer": null,
"skill_id": 119,
"difficulty_id": 2,
"explanation": "Equivalent fractions: $$\\frac{6}{9}$$ simplifies to $$\\frac{2}{3}$$. To get a denominator of 15, multiply numerator and denominator of $$\\frac{2}{3}$$ by 5: $$\\frac{2 \\times 5}{3 \\times 5} = \\frac{10}{15}$$. The missing numerator is 10.",
"hints": ["Find what the denominator 9 (or 3 in simplest form) was multiplied by to get 15.", "Multiply the numerator by the same factor."],
"source": "Nan Hua 2024 P4 Term 2 Review Q10",
"image_needed": false,
"image_options": false,
"image_file": null,
"notes": "Whole-number answer, so FIB. Key: 10."
},
{
"n": 11,
"type_id": 2,
"question": "Peter had 48 apples. He used $$\\frac{2}{3}$$ of them to bake a pie and $$\\frac{1}{6}$$ of them to make apple juice.
(a) How many apples did he use?
(b) How many apples were left?",
"answer0": "40",
"answer1": "8",
"answer2": null,
"answer3": null,
"correct_answer": null,
"skill_id": 122,
"difficulty_id": 2,
"explanation": "(a) Pie: $$\\frac{2}{3} \\times 48 = 32$$ apples. Juice: $$\\frac{1}{6} \\times 48 = 8$$ apples. Used = 32 + 8 = 40 apples. (b) Left = 48 - 40 = 8 apples.",
"hints": ["Find a fraction of a quantity by multiplying the fraction by the total.", "Subtract the apples used from the starting 48."],
"source": "Nan Hua 2024 P4 Term 2 Review Q11",
"image_needed": false,
"image_options": false,
"image_file": null,
"notes": "Two whole-number answers (a then b). Key: a) 40 [via 48/6=8, 8x5=40], b) 8 [48-40]."
},
{
"n": 12,
"type_id": 2,
"question": "A car was filled with 45 $$\\ell$$ of petrol. The car started travelling from 08 00 to 14 00. Petrol was used when the car was moving. The line graph shows the amount of petrol in the car from 08 00 to 14 00.
(a) How much petrol was used from 09 00 to 11 00? (in $$\\ell$$)
(b) At which 1-hour period was the car not moving? (Give the start time then the end time in 24-hour clock.)",
"answer0": "12",
"answer1": "1100",
"answer2": "1200",
"answer3": null,
"correct_answer": null,
"skill_id": 147,
"difficulty_id": 2,
"explanation": "(a) At 09 00 the car had 41 litres; at 11 00 it had 29 litres. Petrol used = 41 - 29 = 12 litres. (b) The car is not moving when petrol stays the same. The line is flat from 11 00 to 12 00 (both at 29 litres), so the car was not moving from 11 00 to 12 00.",
"hints": ["Read the petrol amount off the graph at 09 00 and at 11 00, then subtract.", "When the car is not moving, no petrol is used, so the graph line stays level."],
"source": "Nan Hua 2024 P4 Term 2 Review Q12",
"image_needed": true,
"image_options": false,
"image_file": "q12.png",
"image_page": 8,
"image_bbox": [0.14, 0.27, 0.82, 0.48],
"image_loc": "line graph 'The Amount of Petrol in the Car', amount vs time 08 00 to 14 00, upper-middle of page",
"notes": "Three blanks: (a) litres used, then (b) start time and end time. Key: a) 41-29=12, b) 1100 to 1200."
},
{
"n": 13,
"type_id": 1,
"question": "John used $$\\frac{3}{10}$$ kg of sugar to bake a cake. He used $$\\frac{1}{4}$$ kg of sugar less to make a jelly than to bake the cake. He had $$\\frac{1}{4}$$ kg of sugar left.
(a) How much sugar did he use for the jelly and the cake altogether?",
"answer0": "$$\\frac{7}{20}$$",
"answer1": "$$\\frac{6}{10}$$",
"answer2": "$$\\frac{1}{20}$$",
"answer3": "$$\\frac{11}{20}$$",
"correct_answer": 0,
"skill_id": 122,
"difficulty_id": 3,
"explanation": "Jelly sugar = cake - $$\\frac{1}{4}$$ = $$\\frac{3}{10} - \\frac{1}{4} = \\frac{6}{20} - \\frac{5}{20} = \\frac{1}{20}$$ kg. Altogether (jelly + cake) = $$\\frac{1}{20} + \\frac{6}{20} = \\frac{7}{20}$$ kg.",
"hints": ["First find the jelly amount: cake amount minus 1/4 kg, using a common denominator.", "Add the jelly and cake amounts together."],
"source": "Nan Hua 2024 P4 Term 2 Review Q13",
"image_needed": false,
"image_options": false,
"image_file": null,
"notes": "Part (a) only. Answer is a fraction (7/20 kg), so MCQ not FIB. Key: a) 6/20+1/20 = 7/20 kg. (Part b answer 6/10 also a fraction; this manifest captures part (a).)"
}
]
}