## BEATCALC:  Beat the Calculator!

Back to Calculation Tips & Tricks

 From B. Lee Clay

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### Multiplying a repeating 8's number by 36

1. Choose a repeating 8's number (888, etc.)
2. Multiply it by 36
3. The product is:
- the first two digits are 31
- the next digits are repeating 9's (two fewer than repeating 8's in the original number)
- the last two digits are 68

#### Example:

1. If the first number is 88888:
2. Multiply by 36. The product is:
- the first two digits are 31: 31.
- the next digits are repeating 9's (two fewer than repeating 8's in the original number): 999
- the last two digits are 68: 68.
3. So 88888 × 36 = 3199968.

See the pattern?

1. If the first number is 888888888:
2. Multiply by 36. The product is:
- the first two digits are 31: 31
- the next digits are repeating 9's (two fewer than repeating 8's in the original number): 9999999
- the last two digits are 68: 68.
3. So 888888888 × 36 = 31999999968.
Follow these three steps and you will be giving the big products with ease at the amazement of your associates.