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 ...

Let’s see if you’ve got enough. Why don’t you start by counting up the astro bugs? 1… 2… 3. Then the space grubs. That’s 1… 2… 3… 4… 5. Now all ...