{ "paper": { "school": "Tao Nan", "year": 2023, "level": "P4", "label": "Weighted Assessment 1 and 2", "source_prefix": "Tao Nan 2023 P4 Weighted Assessment 1 and 2", "has_answer_key": true, "notes": "Combined document: WA1 (20 Q) followed by WA2 (20 Q). Manifest numbers WA1 as Q1-Q20 and WA2 as Q21-Q40 to keep unique n; source strings carry the original WA1/WA2 question number. Answer key on pages 25-28 used to cross-check every answer." }, "questions": [ { "n": 1, "type_id": 2, "question": "Write thirteen thousand and forty-three in numerals.
[?]", "answer0": "13043", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 106, "difficulty_id": 1, "explanation": "Thirteen thousand = 13 000. Forty-three = 43. Combine: 13 000 + 43 = 13 043.", "hints": [ "Thirteen thousand is 13 000.", "Add forty-three (43) to it." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q1", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 13043." }, { "n": 2, "type_id": 2, "question": "Use the digits to form the smallest 5-digit even number. Each digit can be used only once.
9, 0, 5, 2, 1
[?]", "answer0": "10592", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 107, "difficulty_id": 2, "explanation": "For the smallest number put small digits first, but the leading digit cannot be 0, so the smallest non-zero digit (1) goes first. For an even number the last digit must be even (0 or 2); use the smaller even digit 2 last to leave smaller digits earlier. Arrange remaining 0, 5, 9 in increasing order: 1, 0, 5, 9, 2 = 10 592.", "hints": [ "The first digit cannot be 0 — pick the smallest non-zero digit.", "An even number must end in an even digit (0 or 2).", "Arrange the rest from smallest to largest." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q2", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 10592." }, { "n": 3, "type_id": 2, "question": "19 508 people visited the National Museum. Round this number to the nearest thousand.
[?]", "answer0": "20000", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 109, "difficulty_id": 1, "explanation": "Look at the hundreds digit of 19 508, which is 5. Since 5 or more rounds up, 19 508 rounds up to 20 000.", "hints": [ "The thousands digit is 9.", "Check the hundreds digit (5) — 5 or more rounds up." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q3", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 20000." }, { "n": 4, "type_id": 2, "question": "Two factors of 27 are 1 and 27. What are the other two factors of 27?
[?] and [?]", "answer0": "3", "answer1": "9", "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 111, "difficulty_id": 1, "explanation": "Factors of 27 are the numbers that divide it exactly: 1, 3, 9, 27. The other two (besides 1 and 27) are 3 and 9.", "hints": [ "A factor divides 27 with no remainder.", "27 = 3 × 9." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q4", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 3 and 9. Order not graded as fixed; accept either order." }, { "n": 5, "type_id": 2, "question": "Complete the following number pattern.
63 865, 62 865, 61 865, 60 865, [?]", "answer0": "59865", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 108, "difficulty_id": 1, "explanation": "Each term decreases by 1000: 63 865, 62 865, 61 865, 60 865. The next term is 60 865 − 1000 = 59 865.", "hints": [ "Find the difference between consecutive terms.", "Each number goes down by 1000." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q5", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 59865." }, { "n": 6, "type_id": 2, "question": "$$5\\frac{2}{7} = \\frac{[?]}{7}$$
What is the missing number in the box?", "answer0": "37", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 119, "difficulty_id": 2, "explanation": "Convert the mixed number to an improper fraction: $$5\\frac{2}{7} = \\frac{5\\times7 + 2}{7} = \\frac{35 + 2}{7} = \\frac{37}{7}$$. The missing numerator is 37.", "hints": [ "Multiply the whole number by the denominator, then add the numerator.", "5 × 7 + 2 = 37." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q6", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 37." }, { "n": 7, "type_id": 0, "question": "In the figure, name the two angles that are greater than 90°.", "answer0": null, "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 99, "difficulty_id": 2, "explanation": "From the figure, the two obtuse angles (greater than 90°) are ∠b and ∠e.", "hints": [ "An angle greater than 90° is obtuse.", "Compare each marked angle to a right angle." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q7", "image_needed": true, "image_options": false, "image_file": "q7.png", "image_page": 4, "image_bbox": [ 0.18, 0.55, 0.55, 0.8 ], "image_loc": "left-centre of page: two intersecting lines forming angles labelled a, b, c, d, e", "notes": "type_id 0: answer names angles (∠b and ∠e) — not a numeric/sequence answer. Answer key: ∠b and ∠e. SKIPPED on insert." }, { "n": 8, "type_id": 2, "question": "Find the sum of all the factors of 10.
[?]", "answer0": "18", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 111, "difficulty_id": 1, "explanation": "Factors of 10 are 1, 2, 5 and 10. Sum = 1 + 2 + 5 + 10 = 18.", "hints": [ "List every number that divides 10 exactly.", "Add them: 1 + 2 + 5 + 10." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q8", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 18." }, { "n": 9, "type_id": 2, "question": "Find ∠GHI.
[?]°", "answer0": "100", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 140, "difficulty_id": 2, "explanation": "Read the protractor: line HI points along the 0° base line and HG lines up with the 100° mark, so ∠GHI = 100°.", "hints": [ "Use the protractor scale starting from the base line HI.", "Read where line HG crosses the scale." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q9", "image_needed": true, "image_options": false, "image_file": "q9.png", "image_page": 5, "image_bbox": [ 0.18, 0.38, 0.7, 0.58 ], "image_loc": "centre of page: a protractor with vertex H, ray HG vertical and ray HI horizontal to the right", "notes": "Answer key: 100°. Answer is degrees value 100." }, { "n": 10, "type_id": 2, "question": "Arrange the following fractions in decreasing order.
$$1\\frac{1}{6}$$, $$\\frac{3}{4}$$, $$\\frac{3}{2}$$
[?], [?], [?]", "answer0": "3/2", "answer1": "1 1/6", "answer2": "3/4", "answer3": null, "correct_answer": null, "skill_id": 119, "difficulty_id": 2, "explanation": "Convert to a common comparison: $$\\frac{3}{2}=1.5$$, $$1\\frac{1}{6}\\approx1.17$$, $$\\frac{3}{4}=0.75$$. Decreasing order is $$\\frac{3}{2}$$, $$1\\frac{1}{6}$$, $$\\frac{3}{4}$$.", "hints": [ "Change each fraction to a decimal or a common denominator.", "Decreasing means largest first." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q10", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 3/2, 1 1/6, 3/4 (decreasing). FIB answers kept plain text." }, { "n": 11, "type_id": 2, "question": "Meiling had some money. She spent $$\\frac{5}{6}$$ of the money and had $18 left. How much money did she have at first?
$[?]", "answer0": "108", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 122, "difficulty_id": 2, "explanation": "She spent $$\\frac{5}{6}$$, so $$\\frac{1}{6}$$ was left = $18. That means 1 unit = $18, and the whole (6 units) = 6 × $18 = $108.", "hints": [ "The fraction left is 1 − 5/6 = 1/6.", "1/6 of the money = $18, so the whole = 6 × $18." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q11", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key working: 1u = $18, 6u = $108." }, { "n": 12, "type_id": 2, "question": "Find the first two common multiples of 4 and 6.
[?] and [?]", "answer0": "12", "answer1": "24", "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 115, "difficulty_id": 2, "explanation": "Multiples of 4: 4, 8, 12, 16, 20, 24... Multiples of 6: 6, 12, 18, 24... The first two common multiples are 12 and 24.", "hints": [ "List multiples of 4 and of 6.", "Find the numbers that appear in both lists." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q12", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 12 and 24." }, { "n": 13, "type_id": 0, "question": "Ahmad is facing north-west. When he turns 225° anticlockwise, which direction will he be facing?", "answer0": null, "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 142, "difficulty_id": 2, "explanation": "Each step on the 8-point compass is 45°; 225° = 5 steps. Turning anticlockwise 5 steps from north-west (NW → W → SW → S → SE → E) ends at east.", "hints": [ "225° ÷ 45° = 5 compass steps.", "Count 5 steps anticlockwise from north-west." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q13", "image_needed": true, "image_options": false, "image_file": "q13.png", "image_page": 6, "image_bbox": [ 0.18, 0.66, 0.42, 0.86 ], "image_loc": "lower-left: an 8-point compass star with N marked at top", "notes": "type_id 0: 8-point-compass direction word (East), removed-syllabus topic, not a value/sequence input. Answer key: East. SKIPPED on insert." }, { "n": 14, "type_id": 2, "question": "Tom and Jerry shared $1550 between them. Jerry received $90 less than Tom. How much money did Jerry receive?
$[?]", "answer0": "730", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 118, "difficulty_id": 2, "explanation": "Remove the $90 difference first: $1550 − $90 = $1460. Split equally between two: $1460 ÷ 2 = $730. This is Jerry's (smaller) share.", "hints": [ "Take away the $90 extra Tom has, then the rest splits equally.", "($1550 − $90) ÷ 2 = Jerry's share." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q14", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: $730." }, { "n": 15, "type_id": 2, "question": "An odd number when rounded to the nearest hundred is 2800. What is the smallest possible value of this odd number?
[?]", "answer0": "2751", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 109, "difficulty_id": 3, "explanation": "Numbers rounding to 2800 range from 2750 to 2849. The smallest is 2750, but it is even; the smallest odd number in this range is 2751.", "hints": [ "Which numbers round to 2800? From 2750 to 2849.", "The smallest is 2750, but it must be odd." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q15", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 2751." }, { "n": 16, "type_id": 2, "question": "Eileen baked 2800 cookies. She sold them in packets of 8 for $7 each. How much money did she collect?
$[?]", "answer0": "2450", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 118, "difficulty_id": 2, "explanation": "Number of packets = 2800 ÷ 8 = 350. Money collected = 350 × $7 = $2450.", "hints": [ "First find how many packets of 8 she made.", "Multiply the number of packets by $7." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q16", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: $2450 (350 packets × $7)." }, { "n": 17, "type_id": 2, "question": "Devi bought 24 curry puffs. She gave 6 curry puffs to her neighbour and her family ate 8 curry puffs. What fraction of the curry puffs were left? Express your answer in its simplest form.
[?]", "answer0": "5/12", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 120, "difficulty_id": 2, "explanation": "Curry puffs left = 24 − 6 − 8 = 10. Fraction left = $$\\frac{10}{24}$$, which simplifies (dividing by 2) to $$\\frac{5}{12}$$.", "hints": [ "First find how many are left: 24 − 6 − 8.", "Write left over total (10/24) and simplify." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q17", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 5/12. FIB fraction answer kept plain a/b." }, { "n": 18, "type_id": 2, "question": "Study the diagram and answer the following questions.
a) Which position is south-west of X?
b) Derek started at Position X. He walked 3 steps due east, 1 step due north and then 3 steps due east. At which position did he end up?
c) Samuel was at a certain position. He walked 2 steps due west and then 1 step due north. He ended at Position G. What was his starting position?
a) Position [?]
b) [?]
c) [?]", "answer0": "A", "answer1": "F", "answer2": "E", "answer3": null, "correct_answer": null, "skill_id": 142, "difficulty_id": 2, "explanation": "Using the grid: a) The position south-west (down-left) of X is A. b) From X, 3 east + 1 north + 3 east lands on F. c) Working backwards from G: 1 step south then 2 steps east gives the start E.", "hints": [ "South-west means down and to the left.", "Trace Derek's path step by step on the grid.", "For Samuel, reverse the moves from G." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q18", "image_needed": true, "image_options": false, "image_file": "q18.png", "image_page": 9, "image_bbox": [ 0.22, 0.16, 0.88, 0.34 ], "image_loc": "top of page: a grid of dots labelled X, A, B, C, D, E, F, G with a 1-step scale and a north arrow on the right", "notes": "Answer key: a) A, b) F, c) E. Three labelled positions as sequence answers; grid figure required." }, { "n": 19, "type_id": 2, "question": "Alice is thrice as old as her cousin. Alice is 39 years old now. What is their total age in 2 years' time?
[?]", "answer0": "56", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 118, "difficulty_id": 2, "explanation": "Cousin's age now = 39 ÷ 3 = 13. In 2 years: Alice = 39 + 2 = 41, cousin = 13 + 2 = 15. Total = 41 + 15 = 56.", "hints": [ "Thrice means 3 times, so cousin = 39 ÷ 3.", "Add 2 years to each, then total." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q19", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 56." }, { "n": 20, "type_id": 2, "question": "Mr Soh planted 27 rows of papaya trees in his orchard. There were 16 trees in each row. $$\\frac{4}{9}$$ of the papaya trees bore fruit. How many papaya trees bore fruit?
[?]", "answer0": "192", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 122, "difficulty_id": 2, "explanation": "Total trees = 27 × 16 = 432. This is 9 units, so 1 unit = 432 ÷ 9 = 48. Trees that bore fruit = $$\\frac{4}{9}$$ = 4 units = 4 × 48 = 192.", "hints": [ "First find the total number of trees: 27 × 16.", "9 units = 432, so find 4 units (4/9)." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA1 Q20", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key working: 9u = 432, 1u = 48, 4u = 192." }, { "n": 21, "type_id": 2, "question": "Find the product of 423 and 56.
[?]", "answer0": "23688", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 116, "difficulty_id": 2, "explanation": "Product means multiply: 423 × 56 = 423 × 50 + 423 × 6 = 21 150 + 2538 = 23 688.", "hints": [ "Product means multiply the two numbers.", "423 × 56." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q1", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 23688." }, { "n": 22, "type_id": 2, "question": "Convert $$1\\frac{7}{25}$$ to a decimal.
[?]", "answer0": "1.28", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 127, "difficulty_id": 2, "explanation": "$$\\frac{7}{25} = \\frac{28}{100} = 0.28$$. Add the whole number: 1 + 0.28 = 1.28.", "hints": [ "Make the denominator 100: 7/25 = 28/100.", "28/100 = 0.28, then add 1." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q2", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 1.28." }, { "n": 23, "type_id": 2, "question": "Express 83 tenths as a decimal.
[?]", "answer0": "8.3", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 123, "difficulty_id": 1, "explanation": "83 tenths = $$\\frac{83}{10}$$ = 8.3.", "hints": [ "83 tenths means 83 ÷ 10.", "Move the decimal point one place." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q3", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 8.3." }, { "n": 24, "type_id": 2, "question": "Find the value of 12 ÷ 5. Give your answer as a decimal.
[?]", "answer0": "2.4", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 125, "difficulty_id": 1, "explanation": "12 ÷ 5 = 2 remainder 2, and $$\\frac{2}{5} = 0.4$$, so 12 ÷ 5 = 2.4.", "hints": [ "12 ÷ 5 = 2 with 2 left over.", "2/5 = 0.4." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q4", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 2.4." }, { "n": 25, "type_id": 2, "question": "Arrange these numbers in increasing order.
4.206, 4.026, 4.26, 4.602
[?], [?], [?], [?]", "answer0": "4.026", "answer1": "4.206", "answer2": "4.26", "answer3": "4.602", "correct_answer": null, "skill_id": 124, "difficulty_id": 2, "explanation": "Compare place by place: 4.026, 4.206, 4.26 (=4.260), 4.602. Increasing order: 4.026, 4.206, 4.26, 4.602.", "hints": [ "Line up the decimal points and compare digit by digit.", "Increasing means smallest first." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q5", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 4.026, 4.206, 4.26, 4.602." }, { "n": 26, "type_id": 2, "question": "Measure ∠x.
[?]°", "answer0": "163", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 140, "difficulty_id": 2, "explanation": "Reading the angle off the protractor against the straight base line, ∠x measures 163°.", "hints": [ "Place the protractor base along the horizontal line.", "Read where the slanted ray crosses the scale." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q6", "image_needed": true, "image_options": false, "image_file": "q26.png", "image_page": 15, "image_bbox": [ 0.22, 0.4, 0.78, 0.55 ], "image_loc": "centre of page: a horizontal line with a ray slanting up to the right, the angle x marked at the vertex", "notes": "Answer key: 163°. Answer is the measured degree value 163." }, { "n": 27, "type_id": 2, "question": "ABCD is a rectangle. Find the length of CD.
[?] cm", "answer0": "14", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 143, "difficulty_id": 1, "explanation": "In a rectangle, opposite sides are equal. AB = 14 cm, and CD is the side opposite AB, so CD = 14 cm.", "hints": [ "Opposite sides of a rectangle are equal.", "CD is opposite AB (14 cm)." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q7", "image_needed": true, "image_options": false, "image_file": "q27.png", "image_page": 15, "image_bbox": [ 0.3, 0.6, 0.72, 0.78 ], "image_loc": "lower-centre: rectangle ABCD with AB marked 14 cm (top) and BC marked 6 cm (right side)", "notes": "Answer key: 14 cm." }, { "n": 28, "type_id": 0, "question": "Draw a square using the given line.", "answer0": null, "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 143, "difficulty_id": 2, "explanation": "Use the given diagonal line on the grid as one side of a square and construct the other three equal sides at right angles to complete a square.", "hints": [ "All four sides of a square are equal.", "Each corner is a right angle." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q8", "image_needed": true, "image_options": false, "image_file": "q28.png", "image_page": 16, "image_bbox": [ 0.28, 0.16, 0.74, 0.36 ], "image_loc": "top: square grid with one short diagonal line segment drawn in the upper-left area", "notes": "type_id 0: 'draw a square' is an interactive drawing task with no app question type. Answer key shows a drawn square. SKIPPED on insert." }, { "n": 29, "type_id": 2, "question": "The figure is made up of rectangle ABCG and square CDEF. Find ∠ECH.
[?]°", "answer0": "60", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 230, "difficulty_id": 3, "explanation": "At point C the angles on the straight line BCD add to 180°. ∠HCB = 75° (given) and ∠ECD = 45° (the diagonal of square CDEF makes 45° with CD). So ∠HCE = 180° − 75° − 45° = 60°.", "hints": [ "Angles on a straight line (BCD) add up to 180°.", "The diagonal of a square makes a 45° angle with its side." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q9", "image_needed": true, "image_options": false, "image_file": "q29.png", "image_page": 16, "image_bbox": [ 0.34, 0.42, 0.62, 0.62 ], "image_loc": "centre: rectangle ABCG joined to square CDEF, with line CH inside and a 75° angle marked at C", "notes": "Answer key working: 75 + 45 = 120, 180 − 120 = 60°. (Key labels it 75+45=120 then 180−120=60.)" }, { "n": 30, "type_id": 1, "question": "Which of the following figures are symmetric?", "answer0": "Figure A and Figure D", "answer1": "Figure A and Figure B", "answer2": "Figure B and Figure C", "answer3": "Figure C and Figure D", "correct_answer": 0, "skill_id": 144, "difficulty_id": 2, "explanation": "A symmetric figure has at least one line of symmetry where the two halves match. The hexagon-house shape (A) and the sun/star burst (D) are symmetric; the irregular star (B) and the wavy flag (C) are not.", "hints": [ "A symmetric figure can be folded so both halves match exactly.", "Check each figure for a line of symmetry." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q10", "image_needed": true, "image_options": false, "image_file": "q30.png", "image_page": 16, "image_bbox": [ 0.18, 0.64, 0.9, 0.8 ], "image_loc": "lower half: four figures labelled A (house/hexagon), B (jagged star), C (wavy flag), D (sun with rays)", "notes": "Converted to MCQ. Answer key: A and D -> option index 0. Figure needed to identify shapes A-D." }, { "n": 31, "type_id": 2, "question": "How many lines of symmetry are there in the figure?
[?]", "answer0": "3", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 145, "difficulty_id": 1, "explanation": "The figure is an equilateral triangle, which has 3 lines of symmetry (one through each vertex to the midpoint of the opposite side).", "hints": [ "The triangle has all sides equal.", "An equilateral triangle has one line of symmetry per vertex." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q11", "image_needed": true, "image_options": false, "image_file": "q31.png", "image_page": 17, "image_bbox": [ 0.34, 0.16, 0.56, 0.3 ], "image_loc": "upper-centre: an equilateral triangle", "notes": "Answer key: 3." }, { "n": 32, "type_id": 0, "question": "Complete the symmetric pattern with XY as the line of symmetry.", "answer0": null, "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 145, "difficulty_id": 2, "explanation": "Reflect each drawn line segment across the vertical line XY so the completed figure is symmetric about XY.", "hints": [ "Each point reflects to the opposite side of XY at the same distance.", "Mirror every segment across the line XY." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q12", "image_needed": true, "image_options": false, "image_file": "q32.png", "image_page": 17, "image_bbox": [ 0.32, 0.4, 0.72, 0.62 ], "image_loc": "centre: a square grid with vertical line of symmetry XY and a few line segments drawn on the left side", "notes": "type_id 0: 'complete the symmetric pattern' is an interactive drawing task. Answer key shows the reflected pattern. SKIPPED on insert." }, { "n": 33, "type_id": 0, "question": "After turning 225° anti-clockwise, Devi was facing north-west. Which direction was Devi facing at first?", "answer0": null, "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 142, "difficulty_id": 2, "explanation": "225° = 5 steps of 45°. To find the starting direction, turn 5 steps clockwise (reverse) from north-west: NW → N → NE → E → SE → S. Devi started facing south.", "hints": [ "225° ÷ 45° = 5 compass steps.", "Reverse the turn: go 5 steps clockwise from north-west." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q13", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "type_id 0: 8-point-compass direction word (South), removed-syllabus topic, not a value/sequence input. Answer key: South. SKIPPED on insert." }, { "n": 34, "type_id": 2, "question": "A fence was 5.6 m long. 1.25 m of the fence was painted red and the rest was painted white. What was the length of the fence that was painted white?
[?] m", "answer0": "4.35", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 129, "difficulty_id": 1, "explanation": "White length = total − red = 5.6 − 1.25 = 4.35 m.", "hints": [ "Subtract the red part from the total length.", "5.6 − 1.25." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q14", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 4.35m." }, { "n": 35, "type_id": 2, "question": "A number is greater than 7.85 but smaller than 7.95. The value of the digit 3 is 0.03. The digit 1 stands for $$\\frac{1}{1000}$$. What is the number? Express your answer as a decimal.
[?]", "answer0": "7.931", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 123, "difficulty_id": 3, "explanation": "The number is between 7.85 and 7.95, so it starts 7.9. The digit 3 has value 0.03, so 3 is in the hundredths place. The digit 1 stands for $$\\frac{1}{1000}$$ = 0.001, so 1 is in the thousandths place. The number is 7.931.", "hints": [ "Between 7.85 and 7.95 means the tenths digit is 9.", "Value 0.03 puts 3 in the hundredths place; 1/1000 puts 1 in the thousandths place." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q15", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 7.931." }, { "n": 36, "type_id": 2, "question": "Wei Jia mixed 0.25 $$l$$ of rose syrup with 1.2 $$l$$ of milk to make Bandung drink for her guests. She then poured the Bandung drink equally into 8 glasses. How much Bandung drink was there in each glass? Give your answer correct to 2 decimal places.
[?] l", "answer0": "0.18", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 131, "difficulty_id": 2, "explanation": "Total drink = 1.2 + 0.25 = 1.45 l. Per glass = 1.45 ÷ 8 = 0.181... which rounds to 0.18 l (2 decimal places).", "hints": [ "Add the syrup and milk first.", "Divide the total by 8, then round to 2 decimal places." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q16", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key working: 1.2 + 0.25 = 1.45, 1.45 / 8 = 0.181, rounds to 0.18 L." }, { "n": 37, "type_id": 2, "question": "The total mass of a box containing a watermelon and a papaya is 3.85 kg. The watermelon is twice as heavy as the papaya. The papaya is twice as heavy as the box. What is the mass of the watermelon?
[?] kg", "answer0": "2.2", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 131, "difficulty_id": 3, "explanation": "Let the box = 1 unit. Papaya = 2 units, watermelon = 2 × papaya = 4 units. Total = 1 + 2 + 4 = 7 units = 3.85 kg, so 1 unit = 3.85 ÷ 7 = 0.55 kg. Watermelon = 4 units = 4 × 0.55 = 2.2 kg.", "hints": [ "Let the box be 1 unit; papaya is 2 units, watermelon is 4 units.", "Total 7 units = 3.85 kg, so find 1 unit then × 4." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q17", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key: 1 unit = 0.55 kg, watermelon = 4 units = 2.2 kg." }, { "n": 38, "type_id": 2, "question": "The figure is made up of a rectangle and a square. Find ∠z.
[?]°", "answer0": "52", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 230, "difficulty_id": 3, "explanation": "The angles 67°, ∠z and 15° together with the right angles of the shapes sit around the vertex. The square contributes 90°: 90° − 67° = 23° above z, and adding the 15° below gives 23° + 15° = 38°; then ∠z = 90° − 38° = 52°.", "hints": [ "A square and a rectangle each have 90° corners at the vertex.", "Use 90 − 67 = 23, then 23 + 15 = 38, then 90 − 38 = 52." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q18", "image_needed": true, "image_options": false, "image_file": "q38.png", "image_page": 21, "image_bbox": [ 0.28, 0.16, 0.78, 0.46 ], "image_loc": "upper-centre: a tilted rectangle and square meeting at a vertex, with 67°, z and 15° marked at the bottom", "notes": "Answer key working: 90 − 67 = 23, 23 + 15 = 38, 90 − 38 = 52, z is 52°." }, { "n": 39, "type_id": 2, "question": "Mrs Khan baked some cupcakes for her students. If she gave each student 3 cupcakes, she would have 5 cupcakes remaining. If she gave each student 4 cupcakes, she would need another 3 cupcakes. How many cupcakes did Mrs Khan bake?
[?]", "answer0": "29", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 118, "difficulty_id": 3, "explanation": "Giving 4 instead of 3 cupcakes per student uses 1 more per student, and the surplus of 5 becomes a shortfall of 3 — a swing of 5 + 3 = 8 cupcakes. So there are 8 students. Cupcakes = 3 × 8 + 5 = 24 + 5 = 29.", "hints": [ "The change from +5 to needing 3 more is a difference of 8 cupcakes for 1 extra each.", "That gives the number of students; then cupcakes = 3 × students + 5." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q19", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key (guess-and-check): 8 students -> 3×8+5 = 29 and 4×8−3 = 29. Mrs Khan baked 29 cupcakes." }, { "n": 40, "type_id": 2, "question": "Emir had $6.40. After giving $1.20 to his brother, Emir had half the amount as his brother. What was the total amount they had altogether?
$[?]", "answer0": "15.60", "answer1": null, "answer2": null, "answer3": null, "correct_answer": null, "skill_id": 131, "difficulty_id": 3, "explanation": "After giving away $1.20, Emir had $6.40 − $1.20 = $5.20. He then had half as much as his brother, so the brother had 2 × $5.20 = $10.40. Total = $5.20 + $10.40 = $15.60. (The total is unchanged by the transfer.)", "hints": [ "First find how much Emir had after giving $1.20 away.", "Emir's amount is half the brother's, so brother = 2 × Emir; add them." ], "source": "Tao Nan 2023 P4 Weighted Assessment 1 and 2 WA2 Q20", "image_needed": false, "image_options": false, "image_file": null, "image_page": null, "image_bbox": null, "image_loc": null, "notes": "Answer key working: $6.40 − $1.20 = $5.20, $5.20 × 3 = $15.60. They had $15.60 altogether." } ] }