Round 17.641 to the nearest whole number

18 - - you look at the number to the right of the whole number - if it is 5 or higher you round up & 4 or lower you round down.

Ur whole number is 17 ... now look at the next number to the right ... if it is 5 or above, u round that 17 to 18 ... if it is 4 or below, that 17 stays the same. And since the next number is 6, u r going to have to round the 17 up to 18 (the nearest whole number)