Primary 1 Mathematics Practice Paper 4

TuitionGoWhere Practice Paper - Mathematics Primary 1

Answer Key and Marking Scheme

Version: 4 of 5
Total Marks: 40

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Section A: Counting and Number Recognition (Questions 1–8)

Question 1 (2 marks)

Answer: 17 (numerals); seventeen (words)

Working/Method:

• Count the stars one by one, or group them to count more easily
• 17 is a two-digit number: 1 ten and 7 ones
• In words: e-lev-en-teen → seventeen (join "seven" and "teen")

Marking notes:

• 1 mark for correct numeral 17
• 1 mark for correct word seventeen (accept minor spelling errors if phonetically reasonable, e.g., "seventen" — use professional judgment)

Common mistake: Writing "70" by reversing digits, or writing "seven teen" as two words.

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Question 2 (2 marks)

Answer: 6 more apples

Working/Method:

• Step 1: Count the apples shown = 14 apples
• Step 2: The target is 20 apples
• Step 3: Find the difference: 20 − 14 = 6
• "How many more" means we need to subtract to find what's missing

Marking notes:

• 2 marks for correct answer 6 (or "6 more apples")
• 1 mark if method shown correctly but arithmetic error made

Common mistake: Adding 14 + 20 = 34 instead of subtracting; misreading the question as "how many altogether."

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Question 3 (2 marks)

Answer: 35; sevens (or "7s")

Working/Method:

• Pattern: 7, 14, 21, 28, ...
• Differences: 14 − 7 = 7, 21 − 14 = 7, 28 − 21 = 7
• This is the 7 times table: counting in sevens
• Next number: 28 + 7 = 35

Marking notes:

• 1 mark for correct next number 35
• 1 mark for identifying pattern as "sevens" or "7s" or "counting in 7s"

Common mistake: Saying "adding 7" instead of "counting in sevens"; answer of 30 (adding 2 to each digit).

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Question 4 (2 marks)

Answer: 17, 32, 45, 50, 89

Working/Method:

• Compare tens first: 17 (1 ten), 32 (3 tens), 45 (4 tens), 50 (5 tens), 89 (8 tens)
• Since all have different tens digits, order by tens: 1 < 3 < 4 < 5 < 8
• Order: 17, 32, 45, 50, 89

Marking notes:

• 2 marks for fully correct sequence
• 1 mark if four numbers in correct order (one number misplaced)
• 0 marks if fewer than four correct

Common mistake: Looking at units digit first (e.g., thinking 89 is smallest because 9 is small); writing 50 before 45 because 5 = 5.

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Question 5 (2 marks)

Answer: 60 (or 6 tens)

Working/Method:

• In 64, the digits are 6 and 4
• 6 is in the tens place
• Value of 6 in tens place = 6 × 10 = 60
• The digit is 6; the value is 60

Marking notes:

• 2 marks for 60 or 6 tens
• 1 mark for answer "6" (confusing digit with value — common early error, note for teaching)
• 0 marks for "4" or "40"

Key concept: Distinguishing digit (the symbol) from value (what it represents due to position).

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Question 6 (2 marks)

Answer: Biggest: 72 (circled); Smallest: 7 (underlined)

Working/Method:

• Compare all numbers: 72, 27, 70, 7
• 72: 7 tens 2 ones
• 27: 2 tens 7 ones
• 70: 7 tens 0 ones
• 7: 0 tens 7 ones (or 7 ones)
• Biggest: 72 (more ones than 70)
• Smallest: 7 (no tens at all)

Marking notes:

• 1 mark for correctly circling 72
• 1 mark for correctly underlining 7
• If student marks are unclear but reasoning evident, accept

Common mistake: Circling 70 as biggest (same tens digit, not checking ones); confusing 7 and 27.

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Question 7 (1 mark)

Answer: 66

Working/Method:

• "10 more than" means add 10
• 56 + 10 = 66
• When adding 10, the tens digit increases by 1, ones stay the same

Marking notes:

• 1 mark for 66

Common mistake: 57 (adding 1 instead of 10); 156 (not understanding place value limits).

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Question 8 (2 marks)

Answer:
(a) 3 tens 4 ones
(b) 58

Working/Method: (a) 34 = 30 + 4, so 3 tens and 4 ones (b) 5 tens = 50, 8 ones = 8, so 50 + 8 = 58

Marking notes:

• 1 mark for each part correct
• For (a): both digits must be correct ("3" and "4")
• For (b): must write full number 58, not "5 tens 8 ones"

Key concept: Place value — position of digit determines its value.

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Section B: Addition and Subtraction Within 100 (Questions 9–16)

Question 9 (2 marks)

Answer: 43

Working/Method:

  28
+ 15
----
  43

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

Full working should show:

• 8 + 5 = 13, regroup 10 ones as 1 ten
• 2 tens + 1 ten + 1 ten = 4 tens

Marking notes:

• 2 marks for correct answer with working shown
• 1 mark for correct method but arithmetic error (e.g., answer 33 from missing carry)

Common mistake: 313 (writing 13 without regrouping); 33 (forgetting to add carried ten).

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Question 10 (2 marks)

Answer: 44

Working/Method:

  73
- 29
----
  44

• Step 1: Ones column: 3 − 9 (can't do, need to borrow/regroup)
  • Take 1 ten from 7 tens → 6 tens left
  • 3 ones becomes 13 ones
  • 13 − 9 = 4 ones
• Step 2: Tens column: 6 − 2 = 4 tens

Marking notes:

• 2 marks for correct answer with working shown
• 1 mark for correct method but subtraction error

Common mistake: 54 (forgetting to reduce tens after borrowing); 44 but no working shown — award 1 mark if answer only.

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Question 11 (2 marks)

Answer: 24 stickers

Working/Method:

• "Gives away" means subtraction (taking away)
• 42 − 18 = ?

  42
- 18
----
  24

• Borrow: 2 → 12 ones, 12 − 8 = 4
• 3 − 1 = 2 tens

Marking notes:

• 2 marks for correct answer with working or clear reasoning
• 1 mark for correct method, calculation error

Common mistake: 42 + 18 = 60 (not reading "gives away" as subtraction).

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Question 12 (2 marks)

Answer: 42 children

Working/Method:

• "Altogether" means addition
• 23 + 19 = ?

  23
+ 19
----
  42

• 3 + 9 = 12, write 2, carry 1
• 2 + 1 + 1 = 4 tens

Marking notes:

• 2 marks for correct answer with working
• 1 mark for correct identification of operation but calculation error

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Question 13 (2 marks)

Answer: 27

Working/Method:

• "What plus 45 makes 72?" → 72 − 45 = ?
• Check: 45 + 27 = 72 ✓

Alternative:

  45 + ? = 72
  ? = 72 - 45 = 27

• 2 − 5 can't do, borrow: 12 − 5 = 7, 6 − 4 = 2

Marking notes:

• 2 marks for 27
• 1 mark for method shown correctly

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Question 14 (2 marks)

Answer: 48 cm

Working/Method:

• "Cut off" means subtraction (taking away)
• 85 − 37 = ?

  85
- 37
----
  48

• 5 − 7 can't do, borrow: 15 − 7 = 8
• 7 − 3 = 4

Marking notes:

• 2 marks for 48 (with or without unit, but encourage "cm")
• 1 mark for working shown correctly

Common mistake: 85 + 37 = 122; forgetting "cut off" indicates subtraction.

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Question 15 (2 marks)

Answer: 40 sweets

Working/Method:

• Method 1 (repeated addition): 8 + 8 + 8 + 8 + 8 = 40
• Method 2 (multiplication concept): 5 groups of 8 = 5 × 8 = 40

Student drawing should show:

• 5 packets with 8 circles/sweets in each
• Total counted: 8, 16, 24, 32, 40

Marking notes:

• 2 marks for correct answer with drawing or working shown
• 1 mark for correct method (drawing 5 groups of 8) but counting error

Key concept: Multiplication as repeated addition or equal groups.

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Question 16 (2 marks)

Answer: 5 cupcakes

Working/Method:

• "Equally into 6 boxes" → sharing/division
• 30 ÷ 6 = ?
• Think: 6 × ? = 30
• 6 × 5 = 30, so 30 ÷ 6 = 5

Or repeatedly subtract: 30 − 6 − 6 − 6 − 6 − 6 = 0 (5 sixes)

Marking notes:

• 2 marks for 5 (accept "5 cupcakes")
• 1 mark for method shown (repeated subtraction or multiplication fact)

Common mistake: 30 + 6 = 36 or 30 − 6 = 24 (not understanding "equally").

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Section C: Applying Your Knowledge (Questions 17–20)

Question 17 (2 marks)

Answer:
(a) $1.60 (or 160¢)
(b) Yes (circled)

Working/Method: (a)

• Two 50¢ coins: 50¢ + 50¢ = 100¢ = $1.00
• Three 20¢ coins: 20¢ + 20¢ + 20¢ = 60¢
• One 10¢ coin: 10¢
• Total: $1.00 +$0.60 + $0.10 = **$1.60** (or 160 cents)

(b) $1.60 >$1.00, so Yes, he has enough.

Marking notes:

• 1 mark for (a): $1.60 or 160¢
• 1 mark for (b): circling Yes
• For (a): accept $1.6 but prefer$1.60 for money notation

Common mistake: Counting coins instead of values (saying "6 coins"); misreading 20¢ as 50¢.

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Question 18 (4 marks)

Answer:
(a) 10 pupils
(b) Orange
(c) 6 pupils

Working/Method:

• Key: Each icon = 2 pupils

(a) Orange: 5 icons × 2 = 10 pupils

(b) Apple: 4 × 2 = 8 pupils
Banana: 3 × 2 = 6 pupils
Orange: 10 pupils
Mango: 2 × 2 = 4 pupils
Orange has the highest number (10 pupils)

(c) Orange − Mango = 10 − 4 = 6 pupils Or: (5 − 2) × 2 = 3 × 2 = 6

Marking notes:

• 1 mark for (a): 10
• 1 mark for (b): Orange
• 2 marks for (c): 6 (1 mark for method: finding difference in icons or pupils; 1 mark for correct answer)

Common mistake: Ignoring the key and counting icons directly (answering 5 for orange instead of 10).

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Question 19 (1 mark)

Answer: 6 : 40 (or 6.40)

Working/Method:

• Minute hand at 8: 8 × 5 = 40 minutes
• Hour hand just past 6: 6 o'clock
• Time: 6:40

Marking notes:

• 1 mark for correct time notation
• Accept "6.40" or "6:40" or "6 40"
• Reject "8:30" or other incorrect readings

Common mistake: Thinking minute hand at 8 means "8 minutes"; reading hour hand as pointing to next hour.

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Question 20 (1 mark)

Answer: 12 cm

Working/Method:

• Pencil starts at 0 cm mark
• Pencil ends at 12 cm mark
• Length = end position − start position = 12 − 0 = 12 cm

Marking notes:

• 1 mark for 12 (or "12 cm")
• Accept reasonable visual estimation if image rendering slightly off; answer should be based on stated values in placeholder

Common mistake: Reading end of pencil at 11 or 13 (not aligning carefully); saying "12" without unit.

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Summary Marking Table

Question	Marks	Topic Skill
1	2	Counting, numerals and words
2	2	"How many more" subtraction
3	2	Number patterns, skip counting
4	2	Ordering numbers
5	2	Place value (value of digit)
6	2	Comparing numbers
7	1	Adding 10 (place value)
8	2	Place value decomposition
9	2	Addition with regrouping
10	2	Subtraction with regrouping
11	2	Subtraction word problem
12	2	Addition word problem
13	2	Inverse (missing addend)
14	2	Subtraction word problem
15	2	Multiplication as equal groups
16	2	Division as equal sharing
17	2	Money calculation, comparison
18	4	Picture graph interpretation
19	1	Telling time
20	1	Measuring length
Total	40

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END OF ANSWER KEY