Maths Library

Missing Number Sentences: Year 4 maths

This topic introduces algebraic thinking and inverse operations through equations with an unknown represented by a box, blank, or symbol. Pupils practise balancing equations, reversing operations, and solving for unknowns in any position.

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What this covers

Missing Number Sentences is taught in Year 4 (age 9 to 10) as a main teaching focus. It sits in the Algebra strand.

Worked example

Find the missing value: __ - 14 = 28

  1. Identify the unknown as the starting quantity (the minuend).
  2. Use the inverse operation: add 14 to 28.
  3. Calculate 28 + 14 = 42. Verify: 42 - 14 = 28.

Answer: 42

Difficulty scale

The sheet generator offers five difficulty settings for this topic.

  1. Missing addend or subtrahend within 20 with unknown at end (e.g., 8 + __ = 15)
  2. Missing values within 50 with unknown at start or middle (e.g., __ - 6 = 23)
  3. Missing values within 100 involving two-digit addition or subtraction
  4. Equations with operations on both sides (e.g., 24 + __ = 50 - 12)
  5. Equations involving basic multiplication or division facts with missing terms

Common mistakes

  • Treating the equals sign as a command to compute rather than a statement of balance
  • Applying the wrong inverse operation (e.g., calculating 50 - 20 instead of 50 + 20 for __ - 20 = 50)

Curriculum links

Indicative matches to Australian Curriculum v9. Check wording and codes against the official document.

  • AC9M4A01 Find missing values in number sentences involving multiplication or division.

Sample sheet and answers

Six questions at the level's usual difficulty. Open the editor to change, add or regenerate any of them.

Missing Number Sentences

Year 4 maths

Qs
6
Marks
18
NameDateScore / 18
1.
5 + = 15
[3]
2.
7 × = 63
[3]
3.
3 + = 15
[3]
4.
7 × = 14
[3]
5.
3 × = 15
[3]
6.
8 + = 16
[3]

Answer key

  1. 1015 − 5 = 10
  2. 963 ÷ 7 = 9
  3. 1215 − 3 = 12
  4. 214 ÷ 7 = 2
  5. 515 ÷ 3 = 5
  6. 816 − 8 = 8