In this module, you can study how to round numbers to a whole number place or to a decimal place.
The video above shows you how to round whole numbers.
The video above shows you how to round numbers to the right of the decimal place.
If you're asked to round off an answer, you wait till you've calculated the answer, THEN you round.
Study and practice
Use these search terms to find additional resources:
rounding decimal numbers
rounding off numbers