3.1 · Part II
Supported Application · Guided Entry to Today's Problem
Understand Ratios · Ratio
- A ratio compares two quantities; order of quantities matters
- Part-to-Part compares two distinct subgroups (e.g. boys to girls)
- Part-to-Whole compares one subgroup to the total (e.g. boys to class)
- Understand Ratios (Comprender razones) — Use a ratio to compare two quantities by division.
- Ratio (Razón) — A way to compare two amounts, like 3 to 2.
- Comparison (Comparación) — Looking at two or more amounts to see how they are related.
- Part-to-part (Parte a parte) — A ratio comparing one part of a group to another part.
- Part-to-whole (Parte a todo) — A ratio comparing one part to the whole group.
- Colon notation (Notación con dos puntos) — Writing a ratio with two dots between the numbers, like 3:2.
- 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 — 3:2 means 3 cups of juice for every 2 cups of water, while 2:3 would mean only 2 cups of juice for every 3 cups of water. Always match the order of your ratio to the order named in the question: "apple juice to sparkling water" means the apple juice number comes first, giving 3:2.
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1 MULTIPLE CHOICE
A pet store has 5 dogs and 9 cats. What is the ratio of dogs to cats?
- A5:9
- B9:5
- C5:14
- D14:5
✏️ Workspace & Solution Steps
Writing Task: Justify why your mathematical solution is accurate and complete.
3.1 · Part II
On-Level Application · Standard Rigor
Understand Ratios · Ratio
- A ratio compares two quantities; order of quantities matters
- Part-to-Part compares two distinct subgroups (e.g. boys to girls)
- Part-to-Whole compares one subgroup to the total (e.g. boys to class)
- Understand Ratios (Comprender razones) — Use a ratio to compare two quantities by division.
- Ratio (Razón) — A way to compare two amounts, like 3 to 2.
- Comparison (Comparación) — Looking at two or more amounts to see how they are related.
- Part-to-part (Parte a parte) — A ratio comparing one part of a group to another part.
- Part-to-whole (Parte a todo) — A ratio comparing one part to the whole group.
- Colon notation (Notación con dos puntos) — Writing a ratio with two dots between the numbers, like 3:2.
- 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 — 3:2 means 3 cups of juice for every 2 cups of water, while 2:3 would mean only 2 cups of juice for every 3 cups of water. Always match the order of your ratio to the order named in the question: "apple juice to sparkling water" means the apple juice number comes first, giving 3:2.
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1 MULTIPLE CHOICE
A fruit salad has 5 pieces of melon, 3 pieces of pineapple, and 2 grapes. What is the ratio of pineapple to melon?
- A3:5
- B5:3
- C3:10
- D3:2
✏️ Workspace & Solution Steps -
2 MULTIPLE CHOICE
A parking lot has 10 cars and 6 trucks. What is the part-to-whole ratio of trucks to total vehicles?
- A6:16
- B10:6
- C6:10
- D16:6
✏️ Workspace & Solution Steps -
3 MULTIPLE CHOICE
Prep Bowl A: Chef Reyes stirs 7 cups of flour with 4 cups of water to make dough. What is the part-to-part ratio of flour to water?
- A7:4
- B4:7
- C7:11
- D11:4
✏️ Workspace & Solution Steps
Writing Task: Justify why your mathematical solution is accurate and complete.
3.1 · Part II
Extension & Non-Routine Application
Understand Ratios · Ratio
- A ratio compares two quantities; order of quantities matters
- Part-to-Part compares two distinct subgroups (e.g. boys to girls)
- Part-to-Whole compares one subgroup to the total (e.g. boys to class)
- Understand Ratios (Comprender razones) — Use a ratio to compare two quantities by division.
- Ratio (Razón) — A way to compare two amounts, like 3 to 2.
- Comparison (Comparación) — Looking at two or more amounts to see how they are related.
- Part-to-part (Parte a parte) — A ratio comparing one part of a group to another part.
- Part-to-whole (Parte a todo) — A ratio comparing one part to the whole group.
- Colon notation (Notación con dos puntos) — Writing a ratio with two dots between the numbers, like 3:2.
- 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 — 3:2 means 3 cups of juice for every 2 cups of water, while 2:3 would mean only 2 cups of juice for every 3 cups of water. Always match the order of your ratio to the order named in the question: "apple juice to sparkling water" means the apple juice number comes first, giving 3:2.
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1 MULTIPLE CHOICE
A class has 12 sixth graders and 18 seventh graders. What is the ratio of sixth graders to the TOTAL number of students, written in simplest form?
- A2 : 5
- B2 : 3
- C12 : 18
- D3 : 5
✏️ Workspace & Solution Steps -
2 MULTIPLE CHOICE
“For every” language: Chef Reyes says, “My glaze uses 9 spoons of honey for every 4 spoons of lemon.” Written in colon notation, the ratio of honey to lemon is:
- A9:4
- B4:9
- C9:13
- D13:4
✏️ Workspace & Solution Steps
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3 OPEN RESPONSE
A bag of marbles has 8 red, 6 blue, and 4 green marbles. Write three different ratios using these quantities: one part-to-part ratio, one part-to-whole ratio, and explain the difference.
✏️ Mathematical Justification & Response
Writing Task: Justify why your mathematical solution is accurate and complete.