Round any number to decimal places or nearest whole, ten, hundred, or custom value. Supports round half up, round up (ceiling), and round down (floor).
Look at the digit after your rounding position. If 5 or more, round up. If 4 or less, keep the preceding digit.
Rounds 0.5 to the nearest even number. So 0.5 rounds to 0 and 1.5 rounds to 2. This reduces cumulative bias in financial calculations.
Rounding adjusts the last digit based on what follows. Truncating simply drops digits. 3.7 rounds to 4 but truncates to 3.
Look at the units digit. If 5 or more round up to the next ten, otherwise keep the current ten. 347 rounds to 350.
Binary cannot exactly represent most decimal fractions. This is why financial software uses decimal arithmetic instead of floating point.