A cube train has eight cubes. If five of them are red, how many
green cubes are there?
In this question, we’re shown a
cube train with eight cubes. So this is our cube train. And we can see that the cube train
has been broken into two parts. We’re told that five of the cubes
are red, but we’re not told how many green cubes there are. Let’s write this information in our
part–whole model. We know the cube train has eight
cubes, and we know the red part has five cubes. Let’s count how many green cubes
there are. There’s one, two, three. The green part has three cubes. If a cube train has eight cubes and
five of them are red, then three of them must be green.