Lesson 1

Using Decimals in a Shopping Context

Let’s use what we know about decimals to make shopping decisions.

Problem 1

Mai had $14.50. She spent $4.35 at the snack bar and $5.25 at the arcade. What is the exact amount of money Mai has left?









Problem 2

A large cheese pizza costs $7.50. Diego has $40 to spend on pizzas. How many large cheese pizzas can he afford? Explain or show your reasoning.

Problem 3

Tickets to a show cost $5.50 for adults and $4.25 for students. A family is purchasing 2 adult tickets and 3 student tickets.

  1. Estimate the total cost.
  2. What is the exact cost?
  3. If the family pays $25, what is the exact amount of change they should receive?

Problem 4

Chicken costs $3.20 per pound, and beef costs $4.59 per pound. Answer each question and show your reasoning.

  1. What is the exact cost of 3 pounds of chicken?

  2. What is the exact cost of 3 pound of beef?

  3. How much more does 3 pounds of beef cost than 3 pounds of chicken?

Problem 5

  1. How many \(\frac15\)-liter glasses can Lin fill with a \(1 \frac12\)-liter bottle of water?
  2. How many \(1 \frac12\)-liter bottles of water does it take to fill a 16-liter jug?
(From Unit 4, Lesson 16.)

Problem 6

Let the side length of each small square on the grid represents 1 unit. Draw two different triangles, each with base \(5\frac12\) units and area \(19\frac14\) units2.

Image of a grid.

Why does each of your triangles have area \(19\frac14 \text{ units}^2\)? Explain or show your reasoning.

(From Unit 4, Lesson 14.)

Problem 7

Find each quotient.

  1. \(\frac56 \div \frac16\)
  2. \(1\frac16 \div \frac{1}{12}\)
  3. \(\frac{10}{6 }\div \frac{1}{24}\)
(From Unit 4, Lesson 10.)