Grade 6 Mathematics · Unit 4: Understand and Use PercentagesStandard 6.AT.4

Lesson 4.3Estimate a Percent of a Number

Start hereWords, worked example, and sentence starters

Name Date Period

Learning target I can estimate the percent of a number using benchmark percents, rounding, and compatible numbers.

Start hereWords for this lesson

Read each word before you begin. Say it out loud.

Word	What it means	Example
estimateSpanish: estimación	A reasoned answer that is close enough to be useful, found without exact computation.	about 22 pounds
benchmark percentSpanish: porcentaje de referencia	A friendly percent — 1%, 10%, 25%, 50%, 75%, 100% — used as a landmark for estimating.	10%, 25%, 50%
compatible numbersSpanish: números compatibles	Numbers close to the originals that are easy to compute with mentally.	216 pounds → 200 pounds
double number lineSpanish: recta numérica doble	Two parallel number lines that pair amounts with their percents at the same positions.	0 · 25% · 50% · 75% · 100% above; 0 · 1.5 · 3 · 4.5 · 6 GB below.
the wholeSpanish: el todo	The quantity that counts as 100% in a problem — and it can change between questions.	“Of the USED storage” makes 4 GB the whole — not the 6 GB total.
DecomposeSpanish: Descomponer	Break a percent into friendly pieces that are easy to find.	15% = 10% + 5%

How it worksWorked exampleestimating a percent of an amount

These numbers are not on your problems. The steps are. Follow them with your own numbers.

A school collected 412 cans. About 18.5% of them were soup cans. About how many soup cans is that?

Round the percent: 18.5% is close to the benchmark twenty percent.
Round the amount: 412 cans is close to the friendly number 400 cans.
Ten percent of 400 cans is 40 cans, and twenty percent is twice that.
The percent was rounded up and the total down, so the estimate runs a bit high.

Answer: About 80 of the cans were soup cans.

Now you trySame steps, your turn

The steps are the same as the worked example. The numbers are yours. Do the work.

A club sold 243 tickets and about 24% of them were student tickets. About how many student tickets is that?

Round the percent to %. Round the ticket count to .
Ten percent of your rounded count is .
Build your rounded percent from that piece:
Estimate: about student tickets

Answer:about how many student tickets

Say it and write itSentence starters

Finish each sentence out loud with a partner. Then use them in your writing.

I rounded to because .
Ten percent of is .
My estimate is about .
My estimate is a little (high / low) because .

Word bank estimateroundcompatible numbersbenchmarkaboutten percenthalfquarterdecomposereasonablehighlow

Watch outA common 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.

Grade 6 Mathematics · Unit 4: Understand and Use PercentagesStandard 6.AT.4

Lesson 4.3Estimate a Percent of a Number

Apply Day · Version ASupported practice

Mastery check☐ Exceeds☐ Meets target☐ Needs practice

Name Date Period

Learning target I can estimate the percent of a number using benchmark percents, rounding, and compatible numbers.

1Complete each step, then write the final answer.

Estimate 10.2% of 798.
Show your work
Hint 10.2% is about 10%. 798 is about 800.
Final answer:
2Complete each step, then write the final answer.

Estimate 24% of 119.
Show your work
Hint 24% is about 25%, which is one quarter. 119 is about 120.
Final answer:
3Complete each step, then write the final answer.

Estimate 48% of 142.
Show your work
Hint 48% is about 50%. Find half of a friendly number near 142.
Final answer:

How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help

Grade 6 Mathematics · Unit 4: Understand and Use PercentagesStandard 6.AT.4

Lesson 4.3Estimate a Percent of a Number

Apply Day · Version BCore practice

Mastery check☐ Exceeds☐ Meets target☐ Needs practice

Name Date Period

Learning target I can estimate the percent of a number using benchmark percents, rounding, and compatible numbers.

1Circle the letter of the best answer. Show how you know.
Jay estimates 52% of 198 as about 200. Is his estimate reasonable?
1. ANo. 52% is about half, so it is about 100.
2. BYes. 198 is about 200.
3. CNo. It is about 52.
Show your work
2Complete each step, then write the final answer.

Estimate 61% of 497. Combine benchmark percents.
Show your work
Final answer:
3Complete each step, then write the final answer.

Estimate 10.7% of 893.
Show your work
Final answer:

How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help

Grade 6 Mathematics · Unit 4: Understand and Use PercentagesStandard 6.AT.4

Lesson 4.3Estimate a Percent of a Number

Apply Day · ChallengeExtension

Mastery check☐ Exceeds☐ Meets target☐ Needs practice

Name Date Period

Learning target I can estimate the percent of a number using benchmark percents, rounding, and compatible numbers.

1Circle the letter of the best answer. Show how you know.
A jacket originally priced at $78.99 is on sale for 25% off. Which is the best estimate of the discount amount?
1. A$8
2. B$10
3. C$20
4. D$40
Show your work
2Complete each step, then write the final answer.

Nia estimates 4.8% of 610. She says 10% of 600 is 60, so the answer is about 60. Find a better estimate.
Show your work
Final answer:
3Complete each step, then write the final answer.

Estimate 73% of 812. Use benchmark percents.
Show your work
Final answer:

How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help