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You did these with your group. Now do them on your own — the model above is yours to copy.

1. 1

   Same stepsFinish what the group started. Use the model above, step for step.

   Try it together — then prove it: A wire is 4 yards long. How many feet long is it? Use 1 yard = 3 feet. Find the scale factor from 1 yard to 4 yards. (4) Multiply 3 feet by 4. How many feet? (12 feet) Why do we multiply to change yards to feet? (A foot is shorter than a yard. It takes more feet to make the same length.)

   Show your work
2. 2

   Warm restartWhich ratio is equivalent to 8:12?

   1. A2:3
   2. B4:8
   3. C8:16
   4. D12:8

   How do you know?
3. 3

   Warm restartFill in the missing value: 5:9 = 20:___

   1. A24
   2. B32
   3. C36
   4. D45

   How do you know?
4. 4

   Warm restartA ratio table shows 7:4 and 21:12. What was each part of 7:4 multiplied by?

   1. A3
   2. B4
   3. C7
   4. D14

   How do you know?

You answered these out loud. Now write them.

Answer, then say how you know — the reason is the part that counts.

1. 5

   Think it throughHow many inches are in 1 foot?

   1. A10
   2. B12
   3. C16
   4. D36

   Why is that the answer?
2. 6

   Think it throughHow many inches tall is the 7-foot cabinet?

   1. A19
   2. B70
   3. C82
   4. D84

   How do you know? Give a second reason as well.
3. 7

   Think it throughWill the cabinet fit through the 80-inch doorway?

   1. ANo, because 84 > 80
   2. BYes, because 84 < 80
   3. CYes, because 7 feet is small
   4. DYou cannot tell without the width

   Explain your thinking. What would have to change for a different choice to be right?
4. 8

   Back to the modelHow do you decide whether to multiply or divide when converting units?

Use the words

Fill each blank with a word from the bank.

• A ratio equal to 1 that relates two units, like 12 inches / 1 foot, is a ___.
• A standard amount used to measure, like a foot or a gram, is a ___.
• Two measurements that name the same amount, like 1 foot and 12 inches, are ___.
• A comparison of two quantities is a ___.

Explain the thinking

1. 9

   Find the mistakeAnother student made this exact mistake in this lesson. Explain why it is wrong, then write what they should have done.

   The mistake: A common mistake in Convert Measurement Units is applying the conversion factor in the wrong direction — for example, converting 4 feet to inches by dividing (4 ÷ 12 = 0.
2. 10

   Say moreHow did you use a conversion factor like '1 ft = 12 in' to fill in the ratio table, and how did you decide whether to multiply or divide?
3. 11

   Write your ownWrite your own problem about this situation, then solve it and show the answer. The situation: Evelyn is visiting family in Canada. The highway sign she sees says 100 kilometers per hour, and she is used to speed limits posted in miles per hour.

   Show your work

Last check

These two come from Lesson 3.9. If they are shaky, that is the lesson to revisit — not this one.

1. 12

   Show what you knowExplain your thinking — Which is the correct conversion of 5 yards to inches?

   1. A15 inches
   2. B60 inches
   3. C180 inches
   4. D540 inches

   Explain your choice.
2. 13

   From Lesson 3.9Explain your thinking — A store sells 5 notebooks for $8. At this rate, how much would 15 notebooks cost?

   1. A$18
   2. B$20
   3. C$24
   4. D$40

   How do you know?
3. 14

   From Lesson 3.9Why must both ingredients be multiplied by the same factor?

   1. ABecause 2 and 3 are both small numbers
   2. BBecause addition would be harder
   3. CSo the total is a whole number
   4. DSo the ratio stays 2:3 and the smoothie tastes the same

   How do you know?

Be honest — this tells your teacher what to do next