Interactive y=mx+b manipulative

Topic:
Algebra
Interactive manipulative of y=mx+b where m and b can be changed. Includes the equation and 3 points.
First set m=2 and b=3. 1. What is the equation of the line? 2. What are some points on the line? Change b up and down. 3. What happens to the line? 4. What happens to the equation? Set b back to 3, change m up and down. 5. What happens to the line? 6. What happens to the equation? 7. See if you can manipulate the line to go through the points (0,1) and (1,0). What is the equation of this line? 8. See if you can manipulate the line to go through the points (0,1) and (-1,0). What is the equation of this line? 9. Can you make a horizontal (side to side) line? If so, what is m? What is the equation of the line? If not, why not? 10. Can you make a vertical (up and down) line? If so, what is m? What is the equation of the line? If not, why not?