Understand Ratios

6.AT.1 · Unit 3 · Lesson 1

Name   Period

Objectives / Objetivos

Content Objective: I can write and describe a ratio that compares two quantities.

Language Objective: I can explain a comparison using the words ratio, part-to-part, part-to-whole, and colon notation.

Key Idea / Idea clave

Understanding Ratios. Formula: a : b | a to b | a/b. 1. A ratio compares two quantities; order of quantities matters. 2. Part-to-Part compares two distinct subgroups (e.g. boys to girls). 3. Part-to-Whole compares one subgroup to the total (e.g. boys to class)

I Notice / Observo

  • What two ingredients are being compared in the recipe?
  • How could you describe the relationship between apple juice and sparkling water?

I Wonder / Me pregunto

  • What if we compared the sparkling water to the apple juice instead — would the ratio change?

Vocabulary / Vocabulario

Term / TérminoDefinition / Definición
Understand Ratios
Comprender razones		Use a ratio to compare two quantities by division.
Usar una razón para comparar dos cantidades mediante la división.
Ratio
Razón		A way to compare two amounts, like 3 to 2.
Una manera de comparar dos cantidades, como 3 a 2.
Comparison
Comparación		Looking at two or more amounts to see how they are related.
Mirar dos o más cantidades para ver cómo se relacionan.
Part-to-part
Parte a parte		A ratio comparing one part of a group to another part.
Una razón que compara una parte de un grupo con otra parte.
Part-to-whole
Parte a todo		A ratio comparing one part to the whole group.
Una razón que compara una parte con todo el grupo.
Colon notation
Notación con dos puntos		Writing a ratio with two dots between the numbers, like 3:2.
Escribir una razón con dos puntos entre los números, como 3:2.

Practice Preview / Vista previa de práctica

Read each task. Show your work in the spaces provided and explain how you know.

1. A recipe uses 4 cups of milk and 1 cup of cream. What is the ratio of milk to cream?

  1. A 1:4
  2. B 4:1
  3. C 4:5
  4. D 5:1

Answer:

2. Sort each statement — is it a part-to-part ratio or a part-to-whole ratio?

Write each item in its correct group.

Word bank: 2 cups sugar to 3 cups flour 3 boys to 5 girls in cooking class 4 vegetarian dishes out of 10 total dishes 5 girls out of 8 students total 7 savory items to 3 sweet items 3 sweet items out of 10 total items
Part-to-Part
Part-to-Whole

3. A fruit salad has 5 pieces of melon, 3 pieces of pineapple, and 2 grapes. What is the ratio of pineapple to melon?

  1. A 3:5
  2. B 3:10
  3. C 3:2
  4. D 5:3

Answer:

4. Find Aliya's Mistake

Which step has the mistake, and what should it be?

Reflection / Reflexión

One thing I learned today / Una cosa que aprendí hoy: