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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.

   Let's do one together: Sheng's car is now worth $26,600, which is 70% of what his parents paid for it. Find the original price. Name the pieces first: $26,600 is the part, 70% is the percent, and the purchase price is the unknown whole. Write the percentage statement as an equation, using the decimal form: 0.7v = 26,600. Solve by dividing both sides by 0.7: v = 26,600 ÷ 0.7 = 38,000. The car cost $38,000 when they bought it.

   My first step is ___ , because the problem asks for ___ .

   Show your work
2. 2

   Warm restartWhat is 10% of 320?

   1. A3.2
   2. B32
   3. C320
   4. D64
3. 3

   Warm restartWhat is 50% of 84?

   1. A50
   2. B34
   3. C168
   4. D42
4. 4

   Warm restartWhat is 20% of 150?

   1. A20
   2. B35
   3. C75
   4. D30

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 through$42 is 60% of the original price. What was the original price?

   1. A$70
   2. B$25.20
   3. C$102
   4. D$60

   Why is that the answer?

   I chose ___ because ___ .
2. 6

   Think it throughWhich equation finds the whole when 75 minutes is 15% of the school day?

   1. A0.15d = 75
   2. B75d = 0.15
   3. Cd = 0.15 × 75
   4. Dd = 75 + 15

   How do you know?

   I chose ___ because ___ .
3. 7

   Think it throughIf the percent given is less than 100%, the whole must be…

   1. ALarger than the part
   2. BSmaller than the part
   3. CEqual to the part
   4. DImpossible to find

   Explain your thinking.

   I chose ___ because ___ .
4. 8

   Back to the modelHow can you tell, before doing any arithmetic, whether the answer should be bigger or smaller than the number you were given?

   If the percent is less than 100%, the given number is a ___, so the whole must be ___ than it.

Sort it again — on paper this time

Write the letter of the group each one belongs in.

• $42 is 60% of what number?
• What is 60% of $70?
• 75 minutes is 15% of the school day. How long is the day?
• 15% of a 500-minute day is how many minutes?
• A car worth $26,600 is 70% of its original price. What did it cost?
• What is 70% of $38,000?

Use the words

Fill each blank with a word from the bank.

• Working backwards from a part and its percent finds the ___.
• How much of the base you get — your answer — is the ___.
• The full amount a percent is measured against is always ___%.
• Two parallel lines pairing amounts with their percents form 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 when finding the whole is multiplying by the percent instead of dividing.
2. 10

   Say moreTo find the whole when 60% is $42, one strategy finds 10% first. Why is 10% such a useful stepping stone, and how does it get you to 100%?

   I found 10% by dividing ___ by ___, which gives ___.
3. 11

   Change one numberGo back to Part 1 and pick one problem you already solved. Change one number in it, then solve your new version. Show every step.

   If ___ changed to ___ , then ___ .

   Show your work

Last check

These two come from Lesson 4.4. If they are shaky, that is the lesson to revisit — not this one.

1. 12

   Show what you knowQuick check — you've got this: A sweater's sale price is $42, which is 60% of the original price. What was the original price?

   1. A$70, because 42 ÷ 0.6 = 70
   2. B$25.20, because 0.6 × 42 = 25.20
   3. C$102, because 42 + 60 = 102
   4. D$60, because the percent is 60

   Explain your choice.

   I know it is ___ because ___ .
2. 13

   From Lesson 4.4Quick check — you've got this: What is 45% of 360?

   1. A162
   2. B45
   3. C315
   4. D180
3. 14

   From Lesson 4.4Check with a benchmark: what is 10% of 1,500?

   1. A150
   2. B15
   3. C1.5
   4. D100

Be honest — this tells your teacher what to do next