Unit 3 Contents

Linda wanted to solve the problem but she did not have grid paper. So she sketched rectangles to show her work. Here is her sketch for 5 29:

3. Use Ana's and Linda's rectangles to answer the questions below:
1. What does the 5 represent?
2. What do the 20 and 9 represent?
3. What does each number in the sentence 5 20 = 100 represent?
4. What does each number in the number sentence 5 9 = 45 represent?
5. How did they find the total number of squares in the large rectangle?
4. Solve the following problems by breaking the larger number into tens and ones. Sketch rectangles like Linda did to show your work.
1. 4 18
2. 5 36
3. 34 6
4. 5 42
5. 8 63
6. 54 9
5. Choose a problem in Question 4. Find a way to solve the problem using mental math. Explain your strategy.

Using Expanded Form

6. Shannon and Ming did not use pictures of rectangles to solve 5 29. They solved the problem by writing 29 in expanded form. Here is how they recorded their work:
   
1. Discuss with a partner what the numbers in Shannon's and Ming's calculations mean.
2. Tell how the numbers in Shannon's problem match Ana's rectangle.