If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Unit 1: Numbers from 1 to 9

400 possible mastery points
Up next for you:

Unit test

Level up on all the skills in this unit and collect up to 400 Mastery points!