How can I round a number to two decimals. Not using the increase/decrease
decimals. For example...

I get an answer like this, 2.41666666666667, I know that if you lower the
decimals to two units, the cell will show the answer 2.42, but if I use this
cell in a calculation it will still use 2.41666666666667, and will give me an
incorrect answer.

100 * 2.41666666666667 = 241.6666667
100 * 2.42 = 242