Suppose tommy walks from his home at (0, 0) to the mall at (0, 7), and then walks to a movie theater at (5, 7). after leaving the theater tommy walks to the store at (5, 0) before returning home. if each grid square represents one block, how many blocks does he walk

For this case, what we must do is find the distance between each ordered pair.
 For this, we use the formula of distance between points.
 We have then:
 

 For (0, 0) and (0, 7):
 
 
 
 
 

 For (0, 7) and (5, 7):
 
 
 
 
 

 For (5, 7) and (5, 0):
 
 
 
 
 

 before returning home the total distance is:
 

 
 before returning home Tommy walks about 19 blocks