## BEATCALC:  Beat the Calculator!

Back to Calculation Tips & Tricks

 From B. Lee Clay

Squaring Numbers

Multiplying Numbers

Dividing Numbers

Subtracting Numbers

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### Multiplying a repeating 8's number by 55

1. Choose a repeating 8's number (888, etc.)
2. Multiply it by 55
3. The product is:
- the first digit is 4
- the next digits are repeating 8's -- one fewer than the repeating 8's in the original number
- the last two digits are 40

#### Example:

1. If the first number is 888:
2. The product is:
- the first digit is 4: 4.
- the next digits are repeating 8's -- one fewer than the repeating 8's in the original number: 88.
- the last two digits are 40: 40.
3. So 55 × 888 = 48840.

See the pattern?

1. If the first number is 88888:
2. The product is:
- the first digit is 4: 4.
- the next digits are repeating 8's -- one fewer than the repeating 8's in the original number: 8888.
- the last two digits are 40: 40.
3. So 55 × 88888 = 4888840.