Luca is connecting a subtraction problem to a two-color counter model. He models the same problem in two ways to show how the subtraction algorithm works. What problem is Luca modeling, and what is Luca showing?
Luca is modeling a subtraction problem using a two-color counter model. He is showing how the subtraction algorithm works by using two different representations.
Luca is modeling a subtraction problem using a two-color counter model. By using two different methods, he is demonstrating how the subtraction algorithm works.
