C Curriculum Explorer
Mathematics·Addition & Subtraction·procedural

Mental addition and subtraction (age 7+)

Mentally add and subtract a three-digit number and ones

Suggested ages 7–8

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Learning journey

Your child is advancing their calculation skills — learning to add and subtract larger numbers up to 1000, mastering mental math strategies, and solving more complex word problems.

Evidence of understanding

  • Calculate 345 + 7 mentally
  • Calculate 462 − 5 mentally
  • Explain that only the ones digit changes (unless bridging through a ten)

Assessment prompt

Can Mental addition and subtraction (age 7+) work out '436 + 7' or '521 − 8' in their head — keeping the hundreds and tens unchanged while adjusting just the ones?

Standards alignment

Ma/KS2/Y3/AS/1aGB · uk-nc-2013

Mental addition/subtraction (ones)

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