## Cost of a Pizza

## Opening

# Cost of a Pizza

Let *p* equal the price in dollars of one Super Combo pizza.

- Write an equation that you could use to find that price.
- How much does each pizza cost?

Let *p* equal the price in dollars of one Super Combo pizza.

- Write an equation that you could use to find that price.
- How much does each pizza cost?

Write and solve equations in order to solve real-world mathematical problems.

There are 78 girls on the track team. This is 5 more than the number of boys on the team. How many boys are on the track team?

- Choose a variable to represent what you want to find out.
- Write an equation that you can use to solve the problem.
- Solve the equation.
- Think about your answer. Does it make sense? Explain.

Let b = the number of boys on the team. What expression has the same value as 78?

The product of $\frac{2}{3}$ and a number is 14.

- Choose a variable to represent what you want to find out.
- Write an equation that you can use to solve the problem.
- Solve the equation.
- Think about your answer. Does it make sense? Explain.

- Choose a variable such as n to represent the number.
- What equation can you write?
- Think about whether your answer should be greater than or less than 14.

Carlos mixed some green paint by using 4 cups of blue paint and 3 cups of yellow paint. He used all of the green paint and wants to make some more. How many cups of blue paint should he mix with 5 cups of yellow paint to get the same color green?

- Choose a variable to represent what you want to find out.
- Write an equation that you can use to solve the problem.
- Solve the equation.
- Think about your answer. Does it make sense? Explain.

- What proportion represents the problem?
- Where will you put the 5 in the proportion?
- What will you multiply or divide by to make the equation easier to work with?

If 3 lb of cheese cost $7, how many pounds of the same cheese can you buy for $25?

- Choose a variable to represent what you want to find out.
- Write an equation that you can use to solve the problem.
- Solve the equation.
- Think about your answer. Does it make sense? Explain.

- What proportion represents the problem?
- Where will you put the 25 in the proportion?

Choose one of the word problems from this lesson to present.

- Explain how you came up with your equation or inequality.
- Explain the steps you took to solve it.

Several friends share a pizza. The price of a plain cheese pizza is $13.00. Each additional topping costs $2.25. The friends pay $24.25 for their pizza.

- Write an equation to represent this situation and then solve it to find out how many additional toppings are on the pizza.

Take notes about the approaches your classmates used to write equations to solve the problems.

As your classmates present, ask questions such as:

- Describe the process that you used to write the equation and solve it.
- How did you decide where to put the 25 in the proportion?
- Is that the only correct way to write the proportion?

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

**When I write an equation for a problem, I …**