What is the nearest whole number for 1.5?

Answer 1

Decimals with at least .5 rounds up.

Decimals with at the greatest .49 round down.

1.5 rounds up, so the nearest whole number is 2.

* * * * *

Nearly there, but not quite. The above does not say what happens to 0.497, for example.

Actually, a rule that always rounds up .5 introduces an upward bias, and a better rule is to:

round down any number less than .5

round up any number greater than .5

and, if the number is .5, then round up or down so that the last [non-zero] digit is EVEN.