{
  "paper": {
    "school": "Nan Hua",
    "year": 2022,
    "level": "P4",
    "label": "Weighted Assessment 1",
    "source_prefix": "Nan Hua 2022 P4 Weighted Assessment 1",
    "has_answer_key": true
  },
  "questions": [
    {
      "n": 1,
      "type_id": 1,
      "question": "Which of the following is sixteen thousand, four hundred and nine in numerals?",
      "answer0": "16 049",
      "answer1": "16 409",
      "answer2": "16 419",
      "answer3": "16 490",
      "correct_answer": 1,
      "skill_id": 106,
      "difficulty_id": 1,
      "explanation": "Sixteen thousand = 16 000, four hundred = 400, and nine = 9. Adding them gives 16 000 + 400 + 9 = 16 409.",
      "hints": ["Write the thousands, hundreds, tens and ones separately.", "Sixteen thousand is 16 000; four hundred and nine is 409."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q1",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q1 = option (2) = 16 409."
    },
    {
      "n": 2,
      "type_id": 1,
      "question": "Which of the following numbers is the smallest?",
      "answer0": "18 769",
      "answer1": "18 796",
      "answer2": "18 902",
      "answer3": "18 931",
      "correct_answer": 0,
      "skill_id": 107,
      "difficulty_id": 1,
      "explanation": "All numbers share 18 thousands. Compare the hundreds: 18 769 and 18 796 have 7 hundreds, smaller than 9. Then compare tens: 6 tens (18 769) is smaller than 9 tens (18 796). So 18 769 is the smallest.",
      "hints": ["Compare digit by digit from the largest place value.", "Two numbers start with 18 7__; compare their tens digits."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q2",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q2 = option (1) = 18 769."
    },
    {
      "n": 3,
      "type_id": 1,
      "question": "In the number pattern, what is the missing number?<br>50 880, 50 910, 50 940, 50 970, ________, 51 030",
      "answer0": "50 100",
      "answer1": "50 980",
      "answer2": "51 000",
      "answer3": "51 020",
      "correct_answer": 2,
      "skill_id": 108,
      "difficulty_id": 1,
      "explanation": "Each term increases by 30 (50 910 - 50 880 = 30). So the missing term is 50 970 + 30 = 51 000. Check: 51 000 + 30 = 51 030.",
      "hints": ["Find the difference between consecutive terms.", "The pattern adds 30 each time."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q3",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q3 = option (3) = 51 000."
    },
    {
      "n": 4,
      "type_id": 1,
      "question": "Which of the following numbers is 38 500 when rounded to the nearest hundred?",
      "answer0": "38 409",
      "answer1": "38 449",
      "answer2": "38 549",
      "answer3": "38 550",
      "correct_answer": 2,
      "skill_id": 109,
      "difficulty_id": 2,
      "explanation": "Rounding to the nearest hundred, the result 38 500 comes from values 38 450 to 38 549. Among the options, 38 549 rounds to 38 500. (38 409 and 38 449 round to 38 400; 38 550 rounds up to 38 600.)",
      "hints": ["A number rounds to 38 500 if it is between 38 450 and 38 549.", "Look at the tens and ones to decide whether to round up or down."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q4",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q4 = option (3) = 38 549."
    },
    {
      "n": 5,
      "type_id": 1,
      "question": "Which of the following is a factor of both 16 and 24?",
      "answer0": "6",
      "answer1": "8",
      "answer2": "40",
      "answer3": "48",
      "correct_answer": 1,
      "skill_id": 113,
      "difficulty_id": 2,
      "explanation": "Factors of 16: 1, 2, 4, 8, 16. Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24. A common factor is 8 (it divides both). 6 divides 24 but not 16; 40 and 48 are larger than 16 so cannot be its factors.",
      "hints": ["A factor must divide the number exactly with no remainder.", "List the factors of 16 first, then check which appear in 24's factors."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q5",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q5 = option (2) = 8."
    },
    {
      "n": 6,
      "type_id": 1,
      "question": "Which of the following is a common multiple of 8 and 12?",
      "answer0": "24",
      "answer1": "20",
      "answer2": "16",
      "answer3": "4",
      "correct_answer": 0,
      "skill_id": 115,
      "difficulty_id": 2,
      "explanation": "Multiples of 8: 8, 16, 24, ... Multiples of 12: 12, 24, 36, ... The number 24 appears in both lists, so it is a common multiple. (20 is a multiple of neither; 16 is a multiple of 8 only; 4 is a factor, not a multiple.)",
      "hints": ["A common multiple must be in both times-tables.", "List multiples of 8 and 12 until you find a shared one."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q6",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q6 = option (1) = 24."
    },
    {
      "n": 7,
      "type_id": 2,
      "question": "Jane spent $1749 in February.<br>She spent $253 less in February than in January.<br>How much did Jane spend in January?",
      "answer0": "$2002",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 2,
      "explanation": "February spending was $253 less than January, so January = February + $253 = $1749 + $253 = $2002.",
      "hints": ["'$253 less in February' means January is the larger amount.", "Add $253 to February's spending."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q7",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q7 = $2002. Answer requires unit $."
    },
    {
      "n": 8,
      "type_id": 2,
      "question": "In a school, there were 832 boys and 164 girls. How many more boys than girls were there?",
      "answer0": "668",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 1,
      "explanation": "Find the difference: 832 - 164 = 668. There are 668 more boys than girls.",
      "hints": ["'How many more' means subtract.", "832 - 164 = ?"],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q8",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q8 = 668."
    },
    {
      "n": 9,
      "type_id": 2,
      "question": "There are 428 sweets in a bottle. Mrs Tan bought 14 bottles to give her pupils. How many sweets did she buy altogether?",
      "answer0": "5992",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 2,
      "explanation": "Multiply sweets per bottle by number of bottles: 428 x 14 = 5992 sweets altogether.",
      "hints": ["'Altogether' with equal groups means multiply.", "428 x 14 = 428 x 10 + 428 x 4."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q9",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q9 = 5992."
    },
    {
      "n": 10,
      "type_id": 2,
      "question": "There are 1048 blue markers in a shop. The number of blue markers is 4 times as many as the number of red markers. How many red markers are there?",
      "answer0": "262",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 2,
      "explanation": "Blue markers are 4 times the red markers, so red markers = 1048 ÷ 4 = 262.",
      "hints": ["'4 times as many' means blue = 4 x red.", "Divide the blue total by 4."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q10",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q10 = 262."
    },
    {
      "n": 11,
      "type_id": 2,
      "question": "Jack jogs 1650 m and Tom jogs 2480 m in a day.<br>How many metres do Jack and Tom jog altogether in 7 days?",
      "answer0": "28910",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 2,
      "explanation": "Total jogged in one day = 1650 + 2480 = 4130 m. Over 7 days = 4130 x 7 = 28 910 m.",
      "hints": ["First find how far they jog together in one day.", "Then multiply the daily total by 7."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q11",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q11 = 28 910 m. Answer requires unit m; stored plain as 28910."
    },
    {
      "n": 12,
      "type_id": 2,
      "question": "Mr Tan saved $4320 in the past 9 months.<br>He saved $100 each month in the first 3 months.<br>He saved the same amount of money each month in the last 6 months.<br>How much did Mr Tan save each month in the last 6 months?",
      "answer0": "$670",
      "answer1": null,
      "answer2": null,
      "answer3": null,
      "correct_answer": null,
      "skill_id": 118,
      "difficulty_id": 3,
      "explanation": "First 3 months saved: $100 x 3 = $300. Remaining over the last 6 months: $4320 - $300 = $4020. Monthly amount in the last 6 months: $4020 ÷ 6 = $670.",
      "hints": ["Work out the total saved in the first 3 months.", "Subtract that from $4320, then divide the rest by 6."],
      "source": "Nan Hua 2022 P4 Weighted Assessment 1 Q12",
      "image_needed": false,
      "image_options": false,
      "image_file": null,
      "notes": "Key Q12 = $670. Answer requires unit $."
    }
  ]
}