Number chains with tens
In a number chain each answer is the start of the next step: 40 + 20 − 10 = 50. Working with full tens, second graders practice keeping a running total in their head.
How to solve this
- A calculation chain links several operations in a row — work strictly from left to right.
- Write down each intermediate result; do not try to skip steps in your head.
- Check by working from right to left using the inverse operations: you should arrive back at the start.
Examples
40 + 20 - 10 = ?
50
36 + 8 - 4 = ?
40
Practice problems with answers
Solve these problems on paper or out loud, then check the answer key. The online practice and the printable worksheet give a new set every time.
- 80 - 30 - 50 + 40 = ___
- 60 + 20 - 30 + 10 = ___
- 20 + 30 + 30 + 10 + 10 = ___
- 40 + 40 + 20 = ___
- 60 + 30 - 40 + 30 - 20 = ___
- 30 + 30 + 10 + 10 + 20 = ___
- 50 - 30 - 10 - 10 = ___
- 90 - 30 - 50 - 10 = ___
Show answers
- 40
- 60
- 100
- 100
- 60
- 100
- 0
- 0