## BEATCALC:  Beat the Calculator!

Back to Calculation Tips & Tricks

 From B. Lee Clay

Squaring Numbers

Multiplying Numbers

Dividing Numbers

Subtracting Numbers

Finding Percents

Calculation
Practice Exercises

Full List

### Multiplying a repeating 9's number by 14

1. Choose a repeating 9's number (999, etc.)
2. Multiply it by 14
3. The product is:
- the first two digits are 13
- the next digits are repeating 9's (two fewer than repeating 9's in the original number)
- the final two digits are 86

#### Example:

1. If the first number is 99999:
2. First two digits are 13.
3. Next digits are repeating 9's -- two fewer than repeating 9's in the original number: 999.
4. Last two digits are 86.
5. So 14 × 99999 = 1399986.

See the pattern?

1. Next pick is 999999999:
2. First two digits are 13.
3. Next digits are repeating 9's -- two fewer than repeating 9's in the original number: 9999999.
4. Last two digits are 86.
5. So 14 × 999999999 = 13999999986.

Follow these three steps and you will be giving these large products with ease. How does that friend do with the second example using his calculator?