How do you round off to the tens place?

Answer 1

Whether to round up or down depends on the digit in the units column. If the unit value is less than 5, you round down, if the unit value is 5 or above, round up.

For example:

12 (The unit column contains a 2, which is less than 5, so round down) becomes 10

15 (The unit column contains a 5, which is 5 or above, so round up) becomes 20