Yasuko Yamaguchi helps students add two numbers using an open number line. Yasuko Yamaguchi helps students add two numbers using an open number line. Let's Learn is available to stream on pbs.org and ...

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 ...