C Curriculum Explorer
Mathematics·Addition & Subtraction·procedural

Adding and subtracting tens mentally

Add and subtract a two-digit number and tens mentally and using concrete/pictorial representations

Suggested ages 6–7

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Learning journey

Your child is building strong foundations in addition and subtraction — learning to add and subtract numbers fluently within 20, understanding the relationship between these operations, and applying various mental strategies to solve problems.

Evidence of understanding

  • Calculate 45 + 30 = 75 mentally
  • Calculate 82 − 40 = 42 mentally
  • Explain that only the tens digit changes when adding/subtracting tens

Assessment prompt

Can Adding and subtracting tens mentally quickly work out '54 + 30' or '78 − 20' in their head — knowing that only the tens digit changes?

Standards alignment

Maths/Y2/AS/5GB · uk-nc-2013

Add and subtract two-digit numbers and tens

The national curriculum in England: Key stages 1 and 2 framework document · Key Stage 1