Grade 3 Math

Mental math strategies

Mental math strategies helps children practise choosing the smartest shortcut for each calculation — rounding, splitting, bridging, or using a known fact. Read the short guide and look through the examples before choosing online practice or a printable worksheet.

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