How do you round 2.8135 to the nearest cent?

2.8135 rounded off to the nearest cent = 2.8

This is because the number at the right of 8 is 1 and 1 is less than 5, so retain 8.

But if the number at the right of 8 is 5 to 9, add 1 to 8. The answer will be 2.9 instead.