Mental math strategies
On this page children practise choosing the smartest shortcut for each calculation — rounding, splitting, bridging, or using a known fact. Start with the short method and the examples, then use the online practice or print a worksheet with answers.
How to solve this
- Mental math strategies let you simplify calculations: round one number, compute, then adjust — e.g. 198 + 47 = 200 + 47 − 2 = 245.
- Other strategies: swap addends for convenience, split one number, or use a known nearby fact.
- Check by estimating: if the exact answer is far from your rounded estimate, recheck the adjustment step.
Examples
99 + 47 (strategy)
146
202 − 98 (strategy)
104
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.
- 539 − 241 = ___
- 24 + 48 = ___
- 333 − 39 = ___
- 22 + 44 = ___
- 372 − 41 = ___
- 772 − 291 = ___
- 308 − 38 = ___
- 99 + 36 = ___
Show answers
- 298
- 72
- 294
- 66
- 331
- 481
- 270
- 135