The strategy
How it works
Break one factor into easy parts, such as tens and ones.
Multiply each part by the other factor.
Add the partial products.
See it in action
Worked examples
Example 114 × 6
- Split 14 into 10 + 4.
- 10 × 6 = 60 and 4 × 6 = 24.
- 60 + 24 = 84.
Answer: 84
Example 223 × 4
- Split 23 into 20 + 3.
- 20 × 4 = 80 and 3 × 4 = 12.
- 80 + 12 = 92.
Answer: 92
A quick heads-up
Common mistakes to avoid
- Multiplying only one part of the split number; write or say both partial products.
- Adding the partial products incorrectly; estimate first so the total is in the right range.
Your turn
Check your understanding
Choose an answer to see instant feedback and a short explanation. You can take the quiz again any time.
Question 1 of 3
What is 12 × 5?
Split 12 into 10 + 2: 10 × 5 = 50 and 2 × 5 = 10; total 60.
What is 21 × 3?
20 × 3 = 60 and 1 × 3 = 3, so 63.
To calculate 16 × 4 by splitting, which parts are useful?
Split 16 into 10 + 6, then multiply both parts by 4.
Keep the momentum
Try a few practice problems
Choose a comfortable range and work through a short round with the free mental math trainer.