To round off a number to its nearest whole number, look at the first number after the decimal point. If the number is equal or greater than 5, add 1 to the number before the decimal point. If it is less than 5, add zero.
Because the first number after the decimal point is 3, which is less than 5, add zero to 16 . 16 + 0 = 16
If the number were 16.571, rounding off to the nearest whole number would give 17
