Addition involves finding the total of two or more numbers or amounts. There are different things you can use to help you add. You can use number lines, place value charts and place value counters.

Practice time! Build, read, & write three-digit numbers using base-10 blocks and symbols. Practice time! Build, read, write (in standard and expanded form), and represent three-digit numbers using ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. This is a number line. Hmm. Where should these numbers go? Let's start with the number 50. It's right ...