Taking away tens works like taking away ones. 8 tens take away 3 tens leaves 5 tens, so 80 − 30 = 50.
When the number has ones, they stay the same: 75 − 40 = 35. Only the tens digit goes down.
On a number line, take away tens by jumping back ten at a time. From 64, jump back three tens: 54, 44, 34. So 64 − 30 = 34. Check by adding: 34 + 30 = 64.
Worked example
90 − 60 =
- 90 is 9 tens and 60 is 6 tens.
- 9 tens − 6 tens = 3 tens.
Answer:30
Key words
- take away
- remove some from a group
- tens
- groups of ten
- left
- how many stay after taking away
Practise this
New questions every time.
Common Core-referenced: 1.NBT.C.6