Multiplying two digit number by 15

1. Select a 2-digit number.
2. Add a zero to it.
3. Divide it by 2.
4. Add the number obtained by dividing by 2 to the last number.

Example:

1. The 2-digit number chosen to multiply by 15 is 62.
2. Add a zero: 620.
3. Find half (divide by 2): 620/2 = 310.
4. Add: 620 + 310 = 930.
5. So 62 × 15 = 930.