Algebra in Real Life

By Michael Every

June 20, 2006

Situation #1

• I have 13 friends coming to my party.• I have ordered 3 pizzas.• The pizzas are cut into 8 pieces.• The pizza boxes are 14x14x1.5 inches.• The party begins at 1:00pm• Steve doesn’t eat pizza.• Frank wants to know how pieces he gets to eat.• I want everyone to get fair share.

What is the Question?

• Let’s go back and look…

Situation #1

• I have 13 friends coming to my party.• I have ordered 3 pizzas.• The pizzas are cut into 8 pieces.• The pizza boxes are 14x14x1.5 inches.• The party begins at 1:00pm• Steve doesn’t eat pizza.• Frank wants to know how many pieces he gets

to eat.• I want everyone to get fair share.

Frank wants to know how many pieces he gets to eat.

• Is this a question?

• Yes

• What information do we need to answer the question?

• Let’s go back and check…

Situation #1

• I have 13 friends coming to my party.• I have ordered 3 pizzas.• The pizzas are cut into 8 pieces.• The pizza boxes are 14x14x1.5 inches.• The party begins at 1:00pm• Steve doesn’t eat pizza.• Frank wants to know how many pieces he gets

to eat.• I want everyone to get fair share.

Situation #1(necessary information)

• I have 13 friends coming to my party.

• I have ordered 3 pizzas.

• The pizzas are cut into 8 pieces.

• Steve doesn’t eat pizza.

• Frank wants to know how many pieces he gets to eat.

• I want everyone to get fair share.

Let’s Create a Balanced Equation.

• What are the given proportions?

• 12 Friends with an equal amount of pizza.

• 3 pizzas with 8 slices each

• 12Friends = 24 slices of pizza

• 12F = 24S

How do we solve our Balanced Equation?

• First decide which variable we need to solve for…F or S?

• Solve for S tells us one Slice feeds many Friends.

• Solve for F tells us one Friend gets how many Slices.

• Correct! Solve for F

Next Step

• We need the F variable by itself.• We can use inverse operations to cancel

values.• 12F = 24S • What is the inverse operation?• Correct! Divide by 12• Remember to keep the equation

balanced…We apply the same operation to both sides

How do I show my work?

12F = 24S

12 12 Divide both sides

by 12

F = 2S

If F = 2S

• Then the answer to Frank’s question is… He gets to eat 2 slices of pizza.

Yeah! We solved our problem

1.)Create an equation

2.)Solve using inverse operations

Balanced Equations

Let’s watch the process in action…

• Click on video to start…

Comprehension Quiz

• Solve with Inverse operations

6X = 18

3+ 2X = 13

More practice

• Homework pages http://teacherweb.com/CA/EIS/Every/

Works Cited

http://www5.unitedstreaming.com/index.cfm