Unit 6 Contents

3. Frank is in Chris's group. He said, “It is easier for me to count up by tens if I can go 50, 60, 70. So I thought of a number line like this:”
   
   1. Where did Frank start? Whose group made that number of hats?
   2. How far is it from where Frank started to where he stopped? Whose group made that number of hats?
   3. How did Frank use tens and ones?
   4. Write a number sentence for Frank's moves on the number line.

Solve the problems in Question 4–10 using a mental math strategy, a number line strategy, or Julia's strategy. Check your solutions using a second strategy. Be prepared to show or tell it to someone else.

4. Chris's group wants to make 50 hats. How many more hats do they need to make?
5. How many more hats did Julia's group make than Chris's?
6. Mara's group made 48 hats and Jason's group made 25 hats. How many hats did the two groups make altogether?
7. How many more hats does Mara's group need to make to have 100 hats?
8. Suzanne's group made 67 hats. How many more hats does Suzanne's group need to make to reach 100?
9. On Monday the class made 151 hats. On Tuesday the class made 146 hats. How many hats did they make on both days altogether?
10. On Wednesday the class has to finish making the 500 hats. How many more hats will the class have to make?

Check-In: Question 11

1. Solve 39 + 71 using a mental math strategy. Show your solution.
2. Show how to solve the problem another way. You may use Julia's strategy, a number line strategy, or one of your own.
3. Which strategy do you like best? Why?

Complete the Use Tens and Ones pages in the Student Activity Book to practice mental math strategies for solving problems.