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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 estimate the metal recycling together: The Green-Team recycled 216 pounds of material; 8.6% was metal. Round both: 8.6% is about 10%, and 216 is about 220. 10% of 220 = 0.1 × 220 = 22. About 22 pounds of metal. Compatible numbers work too: 10% of 200 = 20. Both estimates agree — around 20 pounds.

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

   Show your work

You answered these out loud. Now write them.

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

1. 2

   Think it throughFor the question 'of the USED storage, what percent are photos,' what is the whole (100%)?

   1. A4 GB, the used storage
   2. B6 GB, the total storage
   3. C3.5 GB, the photos themselves
   4. D10 GB, adding the total and used storage together

   Why is that the answer?

   I chose ___ because ___ .
2. 3

   Think it throughOn a double number line built for a whole of 4 GB, what amount lines up with the 75% mark?

   1. A3 GB
   2. B4.5 GB
   3. C3.5 GB
   4. D1 GB

   How do you know?

   I chose ___ because ___ .
3. 4

   Think it throughPhotos take up 3.5 of the 4 GB of used storage. About what percent of the used storage is photos?

   1. AAbout 87%
   2. BAbout 58%
   3. CAbout 35%
   4. DAbout 99%

   Explain your thinking.

   I chose ___ because ___ .
4. 5

   Back to the modelMargaret's phone has 6 GB total and 4 GB used. On the double number line, 4 GB lands between the 50% mark (3 GB) and the 75% mark (4.5 GB), closer to 4.5. Why does that make 'about 70%' a reasonable estimate instead of an exact one?

   4 GB is between the ___% mark and the ___% mark, closer to ___%.

Sort it again — on paper this time

Write the letter of the group each one belongs in.

• Treating 24% as 25% because quarters are easy
• Changing 216 pounds to 200 pounds to divide easily
• Using 10% of a number and scaling from there
• Swapping 81 for 80 before multiplying
• Placing 4 GB between the 50% and 75% marks
• Using 10% and 200 for 8.6% of 216

Use the words

Fill each blank with a word from the bank.

• A reasoned answer close enough to be useful is an ___.
• A friendly percent used as a landmark, like 10% or 25%, is a ___ ___.
• Numbers close to the originals that are easy to compute with are ___ ___.
• Two parallel lines pairing amounts with their percents form a ___ ___ ___.

Explain the thinking

1. 6

   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: Keeping the same whole for every question — when the problem says 'of the used storage,' the whole changes from 6 GB to 4 GB, and estimates anchored to the old whole are wrong before any arithmetic happens.
2. 7

   Say moreYou sorted moves like 'treating 24% as 25%' and 'changing 216 pounds to 200 pounds' into benchmark percent versus compatible numbers. What's the difference between those two strategies?

   Treating 24% as 25% is a benchmark percent because it changes the ___.
3. 8

   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 4.2. If they are shaky, that is the lesson to revisit — not this one.

1. 9

   Show what you knowQuick check — you've got this: Estimate 19% of 412 using benchmarks or compatible numbers.

   1. AAbout 80
   2. BAbout 8
   3. CAbout 200
   4. DAbout 40

   Explain your choice.

   I know it is ___ because ___ .
2. 10

   From Lesson 4.2Quick check — you've got this: Which shows 0.45 as a fraction and a percent?

   1. A9/20 and 45%
   2. B45/10 and 4.5%
   3. C4/5 and 45%
   4. D9/20 and 4.5%
3. 11

   From Lesson 4.2So what do you actually pay for the game?

   1. A$16
   2. B$24
   3. C$26
   4. D$40

Be honest — this tells your teacher what to do next