To round to the nearest ten, you look at the term in the ones place, if it is less than 5 you keep the tens place and round the ones place down to zero, otherwise you round up the tens place and make the ones place equal to zero...
In this case the ones place is 3, which is less than 5, so you keep the tens place, 8, and round the ones place down to 0, leaving you with
180
