## BEATCALC:  Beat the Calculator!

Back to Calculation Tips & Tricks

 From B. Lee Clay

Squaring Numbers

Multiplying Numbers

Dividing Numbers

Subtracting Numbers

Finding Percents

Calculation
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### Multiplying a 2-digit number by 9.6

1. Multiply the number by 6.
2. Move decimal point one place left.
3. Add this to nine times the original number.

#### Example:

1. The 2-digit number chosen to multiply by 9.6 is 21.
2. Multiply by 6: 6 × 21 = 126.
3. Move decimal one place left: 12.6.
4. Add this to nine times the original number: 12.6 + 189 = 2.6 + 199 = 201.6.
5. So 9.6 × 21 is 201.6.

See the pattern?

1. The 2-digit number chosen to multiply by 9.6 is 63.
2. Multiply by 6: 6 × 63 = 360 + 18 = 378.
3. Move decimal one place left: 37.8.
4. Add this to 9 times original number: 37.8 + 9(63) = 37.8 + 540 + 27 = 567 + 37.8 = 597 + 7.8 = 604 + 0.8 = 604.8.
5. So 9.6 × 63 is 604.8.
Remember to multiply and add left to right in easily handled increments. Then you be giving these product with ease.