If a number ends in a five or higher, you will round up. If a number is 4 or lower you will round down.
example:
•35 you would round up to 40
•33 you would round down to 30
264 ends in a four, therefore you should round down to 260.
194 also ends in a four, you should then round down to 190.
34 ends in a four, you would round down to 30.