Dividing a 2-digit number by 12 1/2

1. Select a 2-digit number.
2. Multiply it by 8 (or by 2 three times).
3. Move the decimal point 2 places to the left.

   Example:

1. The 2-digit number chosen to multiply by 12 1/2
   is 78.
2. Multiply by 2 three times:
   2 x 78 = 156
   2 x 156 = 312
   2 x 312 = 624
3. Move the decimal point 2 places to the left: 6.24
4. So 78 divided by 12 1/2 = 6.24.

   See the pattern?

1. If the 2-digit number chosen to multiply by 12 1/2
   is 91:
2. Double three times: 182, 364, 728.
3. Move the decimal point 2 places to the left: 7.28
4. So 91 divided by 12 1/2 = 7.28.

Practice doubling numbers and this should become a fast calculation for you.