You can do this many ways. Write a table that looks like this:
0.25
15
--------
Ignore all decimal points. Multiply the 5's together and carry the 2 to the next column. Multiply 2 x 5 + 2, write the second digit (which is 2) and carry the 1. Multiply 0 by 5 + 1 = 1, so your top number should be 125. Then, multiply all the numbers by the 1. 5 x 1 = 5; 2 x 1 = 2; 0 x 1 = 0. We now have something that looks like:
0.25
15
--------
1 2 5
0 2 5
Add these numbers together and add the decimal point 2 numbers from the right, since that's what was in the original decimal.
