## 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 2-digit number by 59 1/2

1. Select a 2-digit number.
2. Divide by 2.
3. Subtract this from 60 times the original number.

#### Example:

1. The 2-digit number chosen to multiply by 59 1/2 is 21.
2. Divide by 2: 21/2 = 10 1/2.
3. Subtract this from 60 times the original number: 60(21) - 10 1/2 = 1260 - 10 1/2 = 1250 - 1/2 = 1249 1/2.
4. So 21 × 59 1/2 = 1249 1/2.

See the pattern?

1. If the 2-digit number chosen to multiply by 59 1/2 is 56:
2. Divide by 2: 56/2 = 28.
3. Subtract this from 60 times the original number: 60(56) - 28 = 3000 + 360 - 28 = 3360 - 28 = 3340 - 8 = 3332.
4. So 56 × 59 1/2 = 3332.
Multiply and subtract left to right and you will be giving these answers with ease.

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19 July 2004
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