Practice Set · Part 1
Relate Fractions, Decimals, and Percentages
Pick up where we left off
Where we left off
Our goal: I can write equivalent fractions, decimals, and percents for the same value, explain what each part stands for, and build one for a situation I have not seen before.
The big idea: To turn a fraction into a percent, build an equivalent fraction with a denominator of 100: ask “what do I multiply the denominator by to get 100?” and multiply the numerator by that same number. The new numerator is the percent — and you can say why it is true, and where it would stop being true.
Model to copy — Watch me
- A player scored 3/4 of the points. Percent means out of 100, so I want an equivalent fraction with 100 on the bottom.
- What do I multiply the denominator 4 by to get 100? 4 × 25 = 100, so my scale factor is 25.
- I have to multiply the top by that same 25: 3 × 25 = 75. So 3/4 = 75/100.
- 75 out of 100 is 75%. And 75/100 as a decimal is 0.75, because hundredths sit two places after the point.
- So 3/4 = 75/100 = 0.75 = 75%. All three name the same score.
Start here
You did these with your group. Now do them on your own — the model above is yours to copy.
- 1
Same stepsFinish what the group started. Use the model above, step for step.
Try it together — then prove it: Let's change 1/5 into a fraction out of 100, then a decimal and a percent. What do we multiply the denominator 5 by to get 100? (20) Now multiply the numerator by that same 20: 1 × 20 = ? (20) So 1/5 = 20/100. 20 out of 100 is what percent? (20%) And as a decimal? (0.2) Now prove it: say why that move had to work at all — not just that it did.Show your work - 2
Warm restartOn a 100-square grid, 37 squares are shaded. What percent of the grid is shaded?
- A37%
- B0.37%
- C63%
- D3.7%
How do you know?
- 3
Warm restartPercent means 'per ___'.
- A100
- B10
- C1
- D1,000
How do you know?
- 4
Warm restartA tape diagram is split into 4 equal parts and 3 parts are shaded. What percent is shaded?
- A75%
- B34%
- C43%
- D30%
How do you know?
Practice Set · Part 2
Relate Fractions, Decimals, and Percentages
Keep going
You answered these out loud. Now write them.
Answer, then say how you know — the reason is the part that counts.
- 5
Think it through'3/5 off' means 3 of the 5 equal parts come off the price. Which friend is right?
- AThe friend who said 35% off
- BThe friend who said 60% off
- CBoth are the same amount
- DNeither — 3/5 is not a percent
Why is that the answer?
- 6
Think it throughWrite 3/5 as a decimal.
- A0.35
- B0.6
- C3.5
- D0.53
How do you know? Give a second reason as well.
- 7
Think it throughThe game costs $40 and 3/5 comes off. How much is taken off?
- A$14
- B$24
- C$16
- D$35
Explain your thinking. What would have to change for a different choice to be right?
- 8
Back to the modelWhat number did you multiply by to turn each denominator into 100, and how did that fraction out of 100 give you the percent?
Practice Set · Part 3
Relate Fractions, Decimals, and Percentages
Words and reasoning
Word bank · Banco de palabras
Use the words
Fill each blank with a word from the bank.
- Three equivalent ways to name the same part of a whole are ___, ___ and ___.
- A ratio that compares a number to 100, written with a % sign, is a ___.
- A number that uses a point to show parts of a whole is a ___.
- Having the same value but written a different way is being ___.
Explain the thinking
- 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 Relate Fractions, Decimals, and Percents is treating the numerator and denominator as the percent's digits — turning 3/5 into "35%" by just reading the 3 and the 5. - 10
Say moreHow did you turn a fraction like 3/5 into a fraction out of 100, and then into a decimal and a percent?
- 11
Write your ownWrite your own problem about this situation, then solve it and show the answer. The situation: Some middle school students are running a canned food drive. Their goal is to collect 100 cans each week for the local food pantry. So far this week, students have brought in 75 cans.
Show your work
Practice Set · Part 4
Relate Fractions, Decimals, and Percentages
Show what you know
Last check
These two come from Lesson 4.1. If they are shaky, that is the lesson to revisit — not this one.
- 12
Show what you knowExplain your thinking — Which shows 0.45 as a fraction and a percent?
- A9/20 and 45%
- B45/10 and 4.5%
- C4/5 and 45%
- D9/20 and 4.5%
Explain your choice.
- 13
From Lesson 4.1Explain your thinking — Four out of every ten voters chose the tiger. What percent chose the tiger, and how do you know?
- A40%, because 4 out of 10 equals 40 out of 100
- B4%, because 4 voters chose the tiger
- C10%, because the ratio is out of 10
- D14%, because 4 + 10 = 14
How do you know?
- 14
From Lesson 4.1A percent of 150% tells you the amount is…
- A1.5 times the whole
- BHalf the whole
- C150 items
- DImpossible
How do you know?
Be honest — this tells your teacher what to do next
| I can… | Not yet | Getting there | Got it |
|---|---|---|---|
| I can write equivalent fractions, decimals, and percents for the same value, explain what each part stands for, and build one for a situation I have not seen before. | |||
| I can explain why it works: To turn a fraction into a percent, build an equivalent fraction with a denominator of 100: ask “what do I… | |||
| I can justify my answer to a skeptic and connect it to a second strategy or representation. |
One question I want to ask my group next time