## 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 repeating 2's number by 16

1. Choose a repeating 2's number (222, etc.)
2. Multiply it by 16
3. The product is:
- the first digit is 3
- the next digits are repeating 5's (one fewer than repeating 2's in the original number)
- the last digit is 2

#### Example:

1. If the first number is 222222:
2. Multiply by 16. The product is:
- the first digit is 3: 3.
- the next digits are repeating 5's (one fewer than repeating 2's in the original number): 55555.
- the last digit is 2: 2.
3. So 222222 × 16 = 3555552.

See the pattern?

1. If the first number is 2222222222:
2. Multiply by 16. The product is:
- the first digit is 3: 3.
- the next digits are repeating 5's (one fewer than repeating 2's in the original number): 555555555.
- the last digit is 2: 2.
3. So 2222222222 × 16 = 35555555552.
With these three easy steps you will be able to reel off these large products with ease.