Lesson 13
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?
$9.60
$10.60
$4.90
$5.90
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.
- Estimate the total cost.
- What is the exact cost?
- 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.
-
What is the exact cost of 3 pounds of chicken?
-
What is the exact cost of 3 pound of beef?
-
How much more does 3 pounds of beef cost than 3 pounds of chicken?
Problem 5
- How many \(\frac15\)-liter glasses can Lin fill with a \(1 \frac12\)-liter bottle of water?
- How many \(1 \frac12\)-liter bottles of water does it take to fill a 16-liter jug?
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.](https://cms-im.s3.amazonaws.com/vupNoA5g96AkAtsSrCipKyG6?response-content-disposition=inline%3B%20filename%3D%226-6.1.A3.Image.00.Blank-Grid.png%22%3B%20filename%2A%3DUTF-8%27%276-6.1.A3.Image.00.Blank-Grid.png&response-content-type=image%2Fpng&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAXQCCIHWF3XOEFOW4%2F20240718%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20240718T033649Z&X-Amz-Expires=604800&X-Amz-SignedHeaders=host&X-Amz-Signature=7dfe30c0af0c775db3b58f63a49aed51f8e81848c3b7e3f14f22f1585a7cf686)
Why does each of your triangles have area \(19\frac14 \text{ units}^2\)? Explain or show your reasoning.
Problem 7
Find each quotient.
- \(\frac56 \div \frac16\)
- \(1\frac16 \div \frac{1}{12}\)
- \(\frac{10}{6 }\div \frac{1}{24}\)