In Grade 3, students are developing proficiency with representing multidigit addition with base-ten pieces. However, you may find that some students, although professing confidence with the base-ten representation, are in fact still shaky about what is actually happening as they make trades using a paper-and-pencil method—particularly the compact method for addition. As students work on solving problems using paper-and-pencil methods, listen to their conversations and ask questions to make sure they understand the notations they are using.
Ask questions like:
- What does the little “1” you wrote mean?
- When you add the numbers in the tens column what are you adding?
If students are unclear about the mathematical underpinnings of the steps they are doing when performing a paper-and-pencil computation, have them work with the base-ten pieces alongside their paper-and-pencil method. Students having trouble with trades might find the expanded form or all-partials methods helpful as well.
