What do we have?
1. Where is point A on the number line?
2. Where is point B on the number line?
3. What is the length of AB?
4. Click and drag B left and right. Watch the length of AB change.
IMPORTANT: Click & drag point B to be 10 or less!
Let's move AB?
5. Click & drag point A where you want.
The length of AB should not change as you move A!
6. What does change? What stays the same?
What do we now have?
7. NOW where is point A?
8. NOW where is point B?
9. How can we find the length of AB?
10. Find the length of AB?
Let's make up an AB!
11. Type in starting point A between 0 and 10.
12. Type in end point B (bigger than A, but less than 20).
13. Finally, click on Input.
14. What is the length of AB?
• Do this part as many times as you want!