Dividing a 2- or 3-digit number by 2 1/2

1. Select a 2- or 3-digit number.
2. Multiply by 4 (or by 2 twice).
3. Move the decimal point one place to the left.

   Example:

1. The 2-digit number chosen to divide by 2 1/2 is 86.
2. Multiply by 4: 4 x 80 + 4 x 6 = 320 + 24 = 344
3. Move the decimal point one place to the left: 34.4
4. So 86 divided by 2 1/2 = 34.4.

   See the pattern?

1. The 3-digit number chosen to divide by 2 1/2 is 624.
2. Multiply by 2: 2 x 624 = 1248
3. Multiply by 2: 2 x 1248 = 2400 + 96 = 2496
4. Move the decimal point one place to the left: 249.6
5. So 624 divided by 2 1/2 = 249.6.

Multiply by 4 when this is easy; otherwise use two steps and multiply by 2 twice.