## Breaking Eggs

## Opening

# Breaking Eggs

Watch the video.

- What information do you know about this situation?

VIDEO: Broken Eggs

Watch the video.

- What information do you know about this situation?

VIDEO: Broken Eggs

Calculate the unit price of an item and use this rate to find the cost of any number of items.

Carlos wants to buy 9 eggs.

- How much will the 9 eggs cost?
- Include in your solution:
- The quantities involved in the problem
- A diagram, table, double number line, or other representation that shows why your solution makes sense
- An equation, your work, and the solution
- A complete sentence that answers the question

- Remember that there are often multiple ways to solve a math problem. If you have time, try solving this in more than one way.

- Do you think the price will be greater or less than the price of 12 eggs?
- How much would 1 egg cost?
- Does your answer make sense?

- Explain how you determined the cost of 9 eggs.
- Use your work to support your explanation.

- Which is a better buy: $1.79 for 32 ounces of a sports drink, or $0.83 for 12 ounces of the same sports drink?
- Explain your thinking.

Take notes about your classmates’ approaches to solving the problem.

- Determine an approach you will use to solve a different problem involving unit price.

As your classmates present, ask questions such as:

- What are the quantities in this situation?
- What equation did you use?
- Where do you see the price of 1 egg in your equation?
- What operation did you use to find the unit price? Explain your thinking.
- Does your answer make sense? Why?
- If you know the unit price, how do you find the price for any amount of eggs?
- You used an equation and another student used a table to find the cost of 9 eggs. Can you compare the two representations?

Emma buys 3 pounds of apples for $7.50.

- What is the unit price of the apples?

- What are the two quantities in this problem?
- How can you find the cost of 1 pound of apples?
- What operations would you use?
- Does your answer make sense?

Emma changes her mind. Instead of buying 3 pounds of apples for $7.50, she buys 7 pounds.

- How much money will she pay for the apples?

Once you know what 1 pound of apples costs, how can you find the cost of 7 pounds?

Carlos bought a box of cereal. The box contained 16 ounces of cereal and cost him $4.00.

Emma bought a box of a similar cereal. The box contained 24 ounces of cereal and cost her $6.00.

- Who got the better deal? Explain how you know.

- What are the two quantities in this problem?
- How can you find the cost of 1 ounce?
- What operations should you use?
- Does your answer make sense?

**Read and Discuss**

- The unit price is a rate that tells you the price of 1 unit of something—for example, the price of 1 pound of cheese, 1 quart of milk, 1 box of paper clips, 1 package of cereal, and so on.
- The unit price, or rate, can be found by dividing the price in dollars by the number of units.
- The unit price can be used to find the price of any quantity by multiplying the unit price by the quantity.

Can you:

- Explain what
*unit price*means and how to find it? - Include the term
*rate*? - Explain how to find the total price of an item by using its unit price?

Write a reflection about the ideas discussed in class today. Use the sentence starter below if you find it to be helpful.

**As I worked on unit price problems, I found that a useful strategy is …**