Structures to Scaffold Success ◆ 75The Art of the Explanation
The explanation is important. Students have to be taught how to explain
what they did to solve the problem. Practice this with students through
doing think alouds. First, teach students to write about how they read the
problem, decided what was missing and then made a plan. Next, teach
them to discuss both their models and strategies. Finally, teach them to
discuss how their answer addresses the question. This is why it is so
important for students to actually follow a plan when solving the problem
so that they can go back and discuss what they did in some sort of focused
and organized manner (see figures 4.23, 4.24, 4.25 and 4.26).
Figure 4.23
Sue had 2 marbles. Her brother had 5 more than she did. How many did he have?ExplanationI read the problem. It was a compare problem. I was looking for the bigger
part. I added the 5 to the 2 and I got 7. I drew a picture to show my think-
ing. It makes sense.Figure 4.24 Explaining Thinking
David had 5 marbles. Kenny had 2 times as many as David did. How many did
they have altogether?ExplanationI read the problem. I decided it was a compare problem. I had to multiply 2 ×
5 to find the answer. I drew a bar diagram with 5 on top and 2 boxes of 5 on
the bottom because it was 2 times as many. I wrote an equation of 2 × 5. Then,
I added 5 + 10 together and got 15. They had 15 marbles altogether. I checked
the question with my answer and it makes sense.