Primary 1 Mathematics Practice Paper 5

TuitionGoWhere Practice Paper - Mathematics Primary 1

Answer Key with Marking Scheme
Version: 5 of 5
Total Marks: 50 marks

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Section A: Counting and Number Recognition (10 marks)

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Q1. (2 marks)

Expected visual: 2 rows of 5 stars and 1 row of 3 stars (13 stars total)

Working:

• Count all stars: 5 + 5 + 3 = 13

Answer: 13 stars (accept "13")

Marking: 2 marks for correct answer. Deduct 1 mark if answer given without "stars" unit (accept either). Deduct 1 mark if counting error.

Teaching note: Encourage students to count systematically from left to right, top to bottom, touching or marking each star to avoid double-counting or missing any.

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Q2. (2 marks)

Expected visual features from image placeholder (Q2-fig1): Various shapes including 5 triangles among other shapes (4 circles, 3 squares, 2 rectangles)

Working:

• Identify triangles: shapes with exactly 3 sides and 3 corners
• Count carefully: 1, 2, 3, 4, 5

Answer: 5 triangles (accept "5")

Marking: 2 marks for correct answer. 1 mark if student correctly identifies triangles but counts incorrectly (e.g., counts 4 or 6).

Teaching note: Emphasize that triangles always have 3 sides and 3 corners, regardless of orientation. Common mistake: confusing triangles with other pointed shapes or counting shapes with 4 sides.

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Q3. (2 marks)

Working:

• "Just after" means the next number when counting up
• Count up from 29: 29, 30, 31...
• Alternatively: 29 + 1 = 30

Answer: 30

Marking: 2 marks for correct answer.

Teaching note: Distinguish "just after" (next number, +1) from "between" or "just before." Common mistake: writing 31 (counting two steps) or 28 (confusing with "before").

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Q4. (2 marks)

Working:

• 56 = 5 tens and 6 ones
• In words: "fifty" + "six" = fifty-six

Answer: Fifty-six (accept "fifty six" without hyphen)

Marking: 2 marks for correct spelling. 1 mark if numerals "56" are written instead of words, or if minor spelling error that still conveys correct reading.

Teaching note: Connect place value to word form: the tens word (fifty) comes first, then the ones word (six), with a hyphen typically used. Common mistake: writing "fivety-six" or "fifty-6" mixing formats.

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Q5. (2 marks)

Working:

• Compare each number: 38, 83, 33, 88
• Method: Look at tens digit first
  • 33 and 38 have 3 tens (smaller group)
  • 83 and 88 have 8 tens (bigger group)
• Compare within smaller group: 33 vs 38, ones digits 3 < 8
• Therefore 33 is smallest

Answer: 33

Marking: 2 marks for correct answer. No partial marks as this is a straightforward comparison.

Teaching note: Standard method: compare tens digits first, then ones digits if tens are equal. Common mistake: choosing 38 because it "sounds smaller" or comparing digits left to right without attending to place value (thinking 83 is smaller because 8 < 3... which is wrong).

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Section B: Place Value and Number Patterns (10 marks)

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Q6. (2 marks)

Working:

• In 64, digit 6 is in the tens place
• Value = 6 × 10 = 60
• (Not "6" — that would be the digit itself, not its value)

Answer: 60 (accept "6 tens")

Marking: 2 marks for correct value. 1 mark if answer is "6" (confused digit with value). Deduct 1 mark if answer "tens" without the value.

Teaching note: Key concept — "digit" refers to the symbol (6), "value" or "place value" refers to what that digit represents (60 because it's in tens place). Common mistake: answering "6" or "tens" instead of calculating the actual value.

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Q7. (2 marks)

Expected visual features from image placeholder (Q7-fig1): Number boxes showing 15 → 20 → 25 → ?

Working:

• Find the pattern: 20 − 15 = 5, and 25 − 20 = 5
• Pattern rule: add 5 each time
• 25 + 5 = 30

Answer: 30

Marking: 2 marks for correct answer. 1 mark if student identifies pattern as "adding 5" but makes arithmetic error.

Teaching note: Finding the difference between consecutive terms reveals the pattern rule. Students can verify by checking: does 20 − 15 = 25 − 20? Common mistake: guessing without checking consistency, leading to answers like 26 (adding 1 each time after seeing 15, 20...).

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Q8. (2 marks)

Expected visual features from image placeholder (Q8-fig1): Two digit cards showing 2 and 7

Working:

• Possible 2-digit numbers: 27 or 72
• Compare: 27 < 72
• Smallest is 27

Answer: 27

Marking: 2 marks for correct answer. 1 mark if student writes both 27 and 72 but doesn't identify which is smallest, or if writes only 72 (the largest).

Teaching note: To make the smallest number, put the smaller digit (2) in the tens place. To make the largest, put the larger digit (7) in the tens place. Common mistake: putting smaller digit in ones place (72) thinking "smaller digit means smaller number" without considering place value.

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Q9. (2 marks)

Working:

• "10 more than" means add 10
• 45 + 10 = 55
• Using place value: 4 tens + 1 ten = 5 tens, ones stay 5, so 55

Answer: 55

Marking: 2 marks for correct answer. 1 mark if method shows understanding but arithmetic error (e.g., 46, 56).

Teaching note: Adding 10 increases the tens digit by 1 while ones digit stays the same. This is a key pattern for mental calculation. Common mistake: adding 10 to ones place (getting 45 + 10 = 415, or错误地 55 written as 56 by adding to wrong place).

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Q10. (2 marks)

Expected visual features from image placeholder (Q10-fig1): Number line 0–100 with marks every 10, arrow pointing to midpoint between 50 and 60

Working:

• Major marks: 50 and 60
• Arrow is halfway between them
• Halfway between 50 and 60 is 55

Answer: 55

Marking: 2 marks for correct answer. 1 mark if answer is 50 or 60 (identifies nearest marked number but misses estimation). Deduct 1 mark if 54 or 56 (close but not precise enough for this level).

Teaching note: On a number line with intervals of 10, the midpoint represents 5 more than the lower mark. Students should recognize that the arrow position relative to marked numbers helps estimate. Common mistake: reading the nearest labeled number (50 or 60) instead of estimating the position.

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Section C: Comparing and Ordering Numbers (10 marks)

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Q11. (2 marks)

Working:

• Compare tens digits first: 11 and 17 have 1 ten; 71 and 77 have 7 tens
• So 11 and 17 are smaller than 71 and 77
• Compare 11 and 17: ones digits 1 < 7, so 11 < 17
• Compare 71 and 77: ones digits 1 < 7, so 71 < 77
• Order: 11, 17, 71, 77

Answer: 11, 17, 71, 77 (accept without commas if spaces used: 11 17 71 77)

Marking: 2 marks for fully correct order. 1 mark if three numbers in correct relative order but one misplaced, or if reversed order (largest to smallest) with correct relative ordering.

Teaching note: Systematic comparison using tens-then-ones prevents errors. Common mistake: ordering by ones digit (11, 71, 17, 77) or treating 71 as smaller than 17 because 7 < 1 without considering place value.

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Q12. (2 marks)

Working:

• Compare 89 and 98
• Tens digits: 8 < 9
• Therefore 89 < 98, so 98 is greater

Answer: 98

Marking: 2 marks for correct answer.

Teaching note: The common phrase "bigger number has bigger first digit" works when comparing same-length numbers (both 2-digit). Common mistake: choosing 89 because 9 > 8 in ones place, ignoring that tens place determines magnitude first.

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Q13. (2 marks)

Working:

• Mary: 34 stickers
• John: 43 stickers
• Compare: 34 < 43 (3 tens < 4 tens)
• "Fewer" means smaller quantity
• Mary has fewer

Answer: Mary has fewer stickers. (accept "Mary")

Marking: 2 marks for correct name with correct reason implicit. 1 mark if answer "Mary" without "has fewer stickers" phrase. 0 marks if wrong person named.

Teaching note: "Fewer" is used for countable items (stickers), "less" for uncountable quantities. At P1, focus on recognizing that fewer means smaller number. Common mistake: choosing John because he has "more" and student misreads "fewer" as "more."

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Q14. (2 marks)

Working:

• 52 vs 25
• Tens digits: 5 > 2
• Therefore 52 > 25

Answer: 52 > 25

Marking: 2 marks for correct symbol. 1 mark if answer written as "52 is greater than 25" in words instead of symbol.

Teaching note: The "open end" of > or < faces the bigger number, like a mouth eating the bigger number. Common mistake: reversing symbol (<), especially if student reads left-to-right without checking which number is larger.

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Q15. (2 marks)

Working:

• 2-digit numbers range from 10 to 99
• Biggest 2-digit number has largest possible tens and ones digits
• Largest digit is 9, so 99

Answer: 99

Marking: 2 marks for correct answer.

Teaching note: Generalizable: biggest n-digit number is n nines (99, 999, etc.). Smallest n-digit number is 1 followed by zeros (10, 100, etc.). Common mistake: 100 (smallest 3-digit, not 2-digit) or 90 (forgetting ones digit can also be 9).

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Section D: Addition and Subtraction within 100 (15 marks)

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Q16. (3 marks)

Working:

• Start: 28 birds
• Add: 15 more birds
• Calculation: 28 + 15

Step-by-step:

• Add ones: 8 + 5 = 13 ones = 1 ten and 3 ones
• Write down 3, carry 1 ten to tens column
• Add tens: 2 + 1 + 1 (carried) = 4 tens
• Answer: 43

Or decomposition method:

• 28 + 15 = 28 + 10 + 5 = 38 + 5 = 43

Answer: 43 birds

Marking: 3 marks total

• 1 mark: correct method shown (appropriate addition setup)
• 1 mark: correct working with no arithmetic errors
• 1 mark: correct final answer with unit

Deduct 1 mark if answer 43 without "birds" unit. 2 marks if correct method but arithmetic error with carried ten.

Teaching note: The standard algorithm requires understanding place value carrying. Decomposition method (breaking 15 into 10+5) is often more intuitive at P1. Common mistake: forgetting to carry the ten, answering 33 (8+5=13, write 3 but forget carry: 2+1=3, giving 33).

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Q17. (3 marks)

Working:

• Start: 50 sweets
• Subtract: 23 sweets given away
• Calculation: 50 − 23

Step-by-step:

• Ones: 0 − 3, need to regroup
• Regroup: 50 = 4 tens and 10 ones
• Ones: 10 − 3 = 7
• Tens: 4 − 2 = 2
• Answer: 27

Or:

• 50 − 23 = 50 − 20 − 3 = 30 − 3 = 27

Answer: 27 sweets

Marking: 3 marks total

• 1 mark: correct method shown
• 1 mark: correct working with regrouping evident
• 1 mark: correct final answer with unit

2 marks if correct method but regrouping not shown clearly. Deduct 1 mark without unit.

Teaching note: Regrouping (borrowing) is challenging. Concrete representation with base-ten blocks helps before abstract algorithm. Common mistake: 50 − 23 = 33 (subtracting smaller from larger digit regardless of position: 5−2=3, 0−3... treating as 3−0=3).

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Q18. (3 marks)

Working:

• Start: 37 marbles
• End: 62 marbles
• Find: amount added
• Calculation: 62 − 37 = ?

Or: ? + 37 = 62

Step-by-step:

• 62 − 37
• Ones: 2 − 7, need to regroup
• 62 = 5 tens and 12 ones
• Ones: 12 − 7 = 5
• Tens: 5 − 3 = 2
• Answer: 25

Verification: 37 + 25 = 62 ✓

Answer: 25 marbles

Marking: 3 marks total

• 1 mark: correct subtraction setup identified (or correct missing addend approach)
• 1 mark: correct working with regrouping
• 1 mark: correct final answer with unit

2 marks if method correct but arithmetic error. Award 1 mark if student writes 37 + ? = 62 but cannot solve.

Teaching note: This "change unknown" problem type is harder than result unknown. Subtraction finds the difference between start and end. Alternatively, counting up from 37 to 62 works well: 37 to 40 is 3, 40 to 60 is 20, 60 to 62 is 2, total 25. Common mistake: adding 37 + 62 = 99 (wrong operation choice) or 62 − 37 = 35 (regrouping error).

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Q19. (4 marks total)

Expected visual features from image placeholder (Q19-fig1): Pictograph with Apples: 6 symbols, Oranges: 4 symbols, Bananas: 5 symbols; one symbol = one fruit

(a) (1 mark)

Working:

• Count apple symbols: 1, 2, 3, 4, 5, 6

Answer (a): 6 apples (accept "6")

Marking: 1 mark for correct answer.

(b) (2 marks)

Working:

• Bananas: 5
• Oranges: 4
• Difference: 5 − 4 = 1

Answer (b): 1 more banana (accept "1")

Marking: 2 marks total

• 1 mark: correct values identified from graph (5 bananas, 4 oranges)
• 1 mark: correct subtraction and answer

1 mark if correct subtraction setup but arithmetic error.

Teaching note: "How many more" requires comparison (subtraction), not just reading values. Common mistake: answering "5" (just stating banana count) or "1" without showing it's bananas compared to oranges.

(c) (1 mark)

Working:

• Apples: 6
• Oranges: 4
• Bananas: 5
• Total: 6 + 4 + 5 = 15

Or count all symbols: 6 + 4 + 5 = 15

Answer (c): 15 fruits (accept "15")

Marking: 1 mark for correct total. Deduct 1 mark if method shown but arithmetic error.

Teaching note: "Altogether" signals addition of all categories. Common mistake: adding only two categories or repeating count from part (a).

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Q20. (4 marks)

Expected visual features from image placeholder (Q20-fig1): Five children in line, Ali 1st, Ben 5th, blank figures at 2nd, 3rd, 4th

Working:

• Ali is at position 1
• Ben is at position 5
• Positions between them: 2nd, 3rd, 4th
• Count: 3 children

Alternative method:

• 5 − 1 − 1 = 3 (subtract Ali's position and exclude Ben himself, or simply: 5 − 1 = 4 positions from Ali to Ben inclusive, minus Ben = 3, or 5 − 2 = 3 excluding both ends)

Direct counting from diagram:

• Between 1st and 5th: positions 2, 3, 4 → 3 children

Answer: 3 children

Marking: 4 marks total

• 1 mark: correct understanding that "between" excludes endpoints
• 2 marks: correct method shown (counting positions, subtraction with adjustment, or diagram reference)
• 1 mark: correct final answer with unit

3 marks if answer 3 with minimal working but correct. 2 marks if answer 4 (counting Ben or Ali as "between") with otherwise sound method. 1 mark if answer 5 (total in line, misunderstanding question).

Teaching note: "Between" is a crucial vocabulary word — it excludes the endpoints. Many students answer 4 (5 − 1) or 5 (counting all). The visual diagram scaffolds correct counting. Counting actual positions between (2nd, 3rd, 4rd) is most reliable at this level. Common mistakes: 4 (5−1, forgetting to exclude Ben too), 5 (total children in line to 5th position), 2 (rough estimate).

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Summary Mark Distribution

Section	Questions	Marks	Focus
A	1–5	10	Counting, number recognition, basic number writing
B	6–10	10	Place value, patterns, number line
C	11–15	10	Comparing, ordering, relational language
D	16–20	20 (3+3+3+4+4)	Operations, problem solving, data interpretation
Total	1–20	50

Total marks: 50
Duration: 45 minutes
Average time per mark: ~0.9 minutes

Pedagogical Notes for Version 5

This version maintains consistent cognitive demand with versions 1–4 while varying:

• Contexts: birds (Q16), sweets (Q17), marbles (Q18), fruits (Q19), children in line (Q20)
• Number choices: emphasis on regrouping situations (Q16: 28+15; Q17: 50−23; Q18: 62−37)
• Visual complexity: pictograph with three categories requiring multi-step analysis

All questions align with MOE Primary 1 Mathematics syllabus (2021) for Whole Numbers up to 100.