Lesson 3.13.1 Small Group · Group 1
Start hereWords, worked example, and sentence starters
Learning target With my small group, I can write and describe a ratio that compares two quantities — one step at a time, with support.
Why This Matters This is your support small group for Lesson 3.1. We're going to slow this down and build it together, one step at a time. You can ask a question any time — that's what this group is for.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| RatioSpanish: Razón | A way to compare two amounts, like 3 to 2. | 3 to 5 ■■■ □□□□□ |
| ComparisonSpanish: Comparación | Looking at two or more amounts to see how they are related. | 5 eggs vs. 3 eggs — which recipe uses more? |
| Part-to-partSpanish: Parte a parte | A ratio comparing one part of a group to another part. | apples to oranges |
| Part-to-wholeSpanish: Parte a todo | A ratio comparing one part to the whole group. | apples to all the fruit |
| Colon notationSpanish: Notación con dos puntos | Writing a ratio with two dots between the numbers, like 3:2. | 3 to 2 can be written as 3:2 |
| Tape diagramSpanish: Diagrama de cintas | A bar cut into equal parts that shows how two amounts in a ratio compare, and how they make up the whole. | 3 equal parts of apple juice beside 2 equal parts of sparkling water — 5 parts of fruit drink in all. |
How it worksWorked example
These numbers are not on your problems. The steps are. Follow them with your own numbers.
A shelf has 6 math books and 9 reading books. Write reading to math, then math to all books.
- Reading first: 9 : 6.
- All books: 6 + 9 = 15, so math to all is 6 : 15.
- Divide both terms by 3: 6 : 15 = 2 : 5.
Answer: 9 : 6 and 2 : 5
Now you trySame steps, your turn
The steps are the same as the worked example. The numbers are yours. Do the work.
A bowl has 4 apples and 1 orange. Write the ratio of apples to oranges. Then write the ratio of apples to all the fruit.
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
- The ratio of to is .
- This means for every , there are .
- The order matters because .
- I simplified by dividing both terms by .
Word bank ratiotermcomparefor everypartwholetotalsimplest formdivideorderfirstsecond
Watch out!A common mistake
A common mistake in Understand Ratios is writing the ratio in the wrong order: when asked for the ratio of apple juice to sparkling water in a recipe that uses 3 cups of apple juice for every 2 cups of sparkling water, some students write 2:3 (sparkling water to apple juice) because they list the ingredients in whatever order comes to mind rather than the order the question asks for. The two ratios describe different drinks
Lesson 3.13.1 Small Group · Group 1
Group 1Supported practice
Learning target With my small group, I can write and describe a ratio that compares two quantities — one step at a time, with support.
Why This Matters This is your support small group for Lesson 3.1. We're going to slow this down and build it together, one step at a time. You can ask a question any time — that's what this group is for.
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1Complete each step, then write the final answer.
The counts from the problem, in order. A fruit cup has 5 grapes for every 2 strawberries. Write the ratio of grapes to strawberries.
- 1Which fruit do the words name first?
- 2Read the table. Grapes to strawberries is 5 to ?. What is the missing number?
- 3Write the ratio with a colon.
Final answer: -
2Complete each step, then write the final answer.
The Total row is all the players. A team has 6 girls and 5 boys. Write the ratio of boys to all the players.
- 1Add to fill the Total row. How many players are there?
- 2Which number goes first: the boys or all the players?
- 3Write boys to all the players with a colon.
Final answer: -
3Complete each step, then write the final answer.
A bag has 3 red marbles and 8 green marbles. The ratio of green marbles to red marbles is ? : 3. What is the missing number?
Show your workHint Green comes first in this ratio. How many green marbles are there?
Final answer: -
4Complete each step, then write the final answer.
Chef Reyes mixes 4 cups of apple juice with 3 cups of sparkling water. The ratio of apple juice to the whole drink is 4 to ?. What is the missing number?
Show your workHint The whole drink is the juice and the water together.
Final answer: -
5Complete each step, then write the final answer.
A box has 12 crayons. 5 are red and the rest are blue. The ratio of blue crayons to red crayons is ? : 5. What is the missing number?
Show your workHint First find how many crayons are blue. 12 is all the crayons.
Final answer: -
6Circle the letter of the best answer. Show how you know.
Lily has 3 cats and 4 dogs. Ben says the ratio of dogs to cats is 3:4. Which ratio of dogs to cats is correct?
- A4:3
- B3:4
- C4:7
- D3:7
Hint Which animal do the words name first? Its number goes first.
Show your work
Explain your thinkingBen wrote 3:4 for dogs to cats. Why does the order of the numbers matter in a ratio?
Sentence starter Dogs to cats is ___ because the words say ___ first. · If I switch the order, the ratio compares ___ to ___.