Math
Understand the structure, not just the steps.
Build number sense, problem-solving habits and efficient methods that still make sense when the numbers change.
Example: 25 × 16 without long multiplication
You can split 16 into 4 × 4. Then:
25 × 16 = 25 × 4 × 4 = 100 × 4 = 400The trick works because multiplication can be regrouped without changing the product.
A second method is to use 16 = 8 × 2:
25 × 8 = 200, then 200 × 2 = 400.
Why this matters
Mental math is not about memorizing isolated tricks. It is about noticing structure: friendly numbers, factors, place value and equivalent expressions.
Practice
- 25 × 24
- 50 × 18
- 125 × 16
- Explain why 25 × 9 + 9 is not the same as 25 × 10.