## BEATCALC:  Beat the Calculator!

Back to Calculation Tips & Tricks

 From B. Lee Clay

Squaring Numbers

Multiplying Numbers

Dividing Numbers

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### Multiplying a repeating 3's number by 99

1. Choose a repeating 3's number (333, etc.)
2. Multiply it by 99
3. The product is:
- the first two digits are 32
- the next digits are repeating 9's (two fewer than repeating 3's in the original number)
- the final two digits are 67

#### Example:

1. If the first number is 3333:
2. First two digits are 32.
3. Next digits are repeating 9's -- two fewer than repeating 3's in the original number: 99.
4. Last two digits are 67.
5. So 99 × 3333 = 329967.

See the pattern?

1. Next pick is 333333:
2. First two digits are 32.
3. Next digits are repeating 9's -- two fewer than repeating 3's in the original number: 9999.
4. Last two digits are 67.
5. So 99 × 333333 = 32999967.

Follow these three steps and you will be able to give these large products with ease.