1. Module 2 Lesson 7 - Measure and compare lengths using standard metric length units and non-standard length units; relate measurement to units and non-standard length units; relate measurement to unit size

2. Fluency Practice Which is shorter? I am going to say two lengths. Tell me which length is shorter. Ready? 6 centimeters or 10 centimeters? 6 centimeters! Give the number sentence to find how much shorter 10cm – 6cm = 4cm

3. Fluency Practice Which is shorter? Ready? 12 centimeters or 22 centimeters? 12 centimeters! Give the number sentence to find how much shorter 22cm – 12cm = 10cm

4. Fluency Practice Ready? 16 centimeters or 20 centimeters? 16 centimeters! Give the number sentence to find how much shorter 20cm – 16cm = 4cm

5. Fluency Practice Ready? 20 centimeters or 13 centimeters? 13 centimeters! Give the number sentence to find how much shorter 20cm – 13cm = 7cm

6. Fluency Practice Ready? 20 centimeters or 9 centimeters? 9 centimeters! Give the number sentence to find how much shorter 20cm – 9cm = 11cm

7. Fluency Practice Ready? 9 centimeters or 19 centimeters? 9 centimeters! Give the number sentence to find how much shorter 19cm – 9cm = 10cm

8. Fluency Practice Ready? 24 centimeters or 14 centimeters? 14 centimeters! Give the number sentence to find how much shorter 24cm – 14cm = 10cm

9. Fluency Practice Ready? 12 centimeters or 24 centimeters? 12 centimeters! Give the number sentence to find how much shorter 24cm – 12cm = 12cm

10. Fluency Practice Ready? 23 centimeters or 15 centimeters? 15 centimeters! Give the number sentence to find how much shorter 23cm – 15cm = 8cm

11. Fluency Practice Ready? 18 centimeters or 29 centimeters? 18 centimeters! Give the number sentence to find how much shorter 29cm – 18cm = 11cm

12. Application Problem Luigi has 9 more books than Mario. Luigi has 52 books. How many books does Mario have? L M 52 - 9 = L52 M? 9 52-9= 42 1042 10 10-9=1 42+1= 43 43 Mario has 43 books.

13. Concept Development Measure your straw with your paper clips I am going to give each table a paper bag and paper clips to measure with. How long is the straw?

14. Concept Development Why do you think the measurements are different? Turn and talk. Take out your crayon and measure with your paper clips. Share your measurement with your partner. Let’s switch bags with our neighbors and measure again.

15. Concept Development Were your measurements different? Why? Why does the size of my paper clip matter? What does that tell you about measurement and unit size? Let’s measure again using small and big paper clips mixed together.

16. Concept Development What were your results? Why are all these measurements different? Crayon - Straw - So, if I wanted to order a table and I told you I want it to be 80 paper clips long, what might happen?

17. Concept Development Lets measure some more of these objects using centimeter rulers What do you notice about the measurements when we use a centimeter ruler? What were some results? Crayon - Eraser - Straw -

18. Concept Development Why is it more efficient to measure with a centimeter instead of paper clips? What is the same about all the rulers?

19. Problem Set

21. Student Debrief - Turn to your partner and compare your answers to Problems 1 and 2. Which math strategies did you use to determine which line was longer or shorter? - Look at Problem 4. Turn and talk to your partner about why Christina’s answer is incorrect. - Do you think that paper clips are a reliable measurement tool? Is a ruler a better measurement tool? Why?