Mathematics·Addition & Subtraction·procedural
Mentally adding tens to 3-digit numbers
Mentally add and subtract a three-digit number and tens
Suggested ages 7–8
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 + 40 mentally
- Calculate 462 − 30 mentally
- Explain that only the tens digit changes (unless bridging through a hundred)
Assessment prompt
Can Mentally adding tens to 3-digit numbers quickly work out '354 + 40' or '628 − 30' in their head — knowing that only the tens digit changes?
Standards alignment
Ma/KS2/Y3/AS/1bGB · uk-nc-2013
Mental addition/subtraction (tens)
The national curriculum in England: Key stages 1 and 2 framework document · Key Stage 2