Which 3 go together?

Tyler and Clare subtract by place to find the value of . Tyler says he will decompose before he starts. Clare agrees.

The diagrams show each student’s first steps.

Tyler

Clare

1. How are Tyler’s and Clare’s diagrams alike? How are they different?
2. Complete their diagrams to find the value of .
3. What do Tyler’s and Clare’s diagrams look like after the last step? How are these diagrams alike? How are they different?

Here is a base-ten diagram for 341.

Andre wants to use diagrams and subtract by place to find the value of . He says he will decompose a ten and a hundred to subtract. Why do you think he said that?

1. Andre only wants to use a diagram to subtract by place if he decomposes a unit. Help him sort the expressions into groups. You can use base-ten blocks or a diagram to help.

   decompose 2 units	decompose 1 unit	do not decompose

2. Find the value of 1 expression from each group. Show your thinking, using drawings, numbers, or words.