Percents Greater than 100%

Percents Greater than 100%

Too Much Rain

Opening

Too Much Rain

The city of Valley View normally gets 20 inches of rain per year.

Last year the city got 25 inches of rain.

Think of using percents to compare 25 inches of rain as a percent of the normal rainfall.

  • Will this be greater than or less than 100%?
  • What strategies can be used to solve this problem?

Math Mission

Opening

Solve problems that involve percents greater than 100%.

Rain

Work Time

Rain

The city of Valley View normally gets 20 inches of rain per year.

Last year the city got 25 inches of rain.

  • Calculate last year’s rainfall as a percent of normal.

To calculate the percent, would you divide 20 by 25 or divide 25 by 20?

Company Earnings

Work Time

Company Earnings

A company earned $9,000 in July.

That amount is 120% of the company’s normal earnings for the month of July.

  • What are the company’s normal earnings for the month of July?

Will the answer to this problem be greater than $9,000 or less than $9,000?

True Statement?

Work Time

True Statement?

Look at each statement and decide whether or not it could be true.

If the statement could be true, provide details about the situation in the statement that explain how the statement could be true.

If the statement could not be true, explain why.

  • 125% of the students are absent today.
  • The snowfall last year was 150% of normal.

Think about the situation. Does the statement make sense for that situation?

Prepare a Presentation

Work Time

Prepare a Presentation

Explain your solution to one of the Work Time tasks. Support your explanation with diagrams and equations.

Challenge Problem

  • What is 150% of 0.5?
  • Use fractions or sketch a diagram to represent the problem and show your solution strategy.

Make Connections

Performance Task

Ways of Thinking: Make Connections

Take notes about the approaches your classmates used for solving problems with percents greater than 100%.

As your classmates present, ask questions such as:

  • Can you make a diagram to illustrate what you are saying?
  • Can you write an equation or expression that represents the relationship you are describing?
  • Did you use the context of the problem (that is, what it was about—money, attendance, rainfall, or snowfall) to help you check that your answer made sense? If not, how do you think the context of a problem might help you determine whether your answer makes sense?

Percents Greater Than 100%

Formative Assessment

Summary of the Math: Percents Greater Than 100%

Write a summary of what you learned about percents greater than 100%.

Check your summary.

  • Do you explain what it means for a percent to be greater than 100%?
  • Do you give examples of the types of situations in which percents greater than 100% make sense?

Using Tools to Solve Ratio Problems

Formative Assessment

Using Tools to Solve Ratio Problems

Complete this Self Check by yourself. Use a tool such as the Ratio Table, Double Number Line, or a graph to solve the problem.

A waiter at a restaurant shares his tips with the busboy in the ratio 5:2 (5 parts for himself, 2 for the busboy).

  • If the waiter had $45 after sharing his tips, how much did he give the busboy?
  • Explain how you got your answer.

INTERACTIVE: Double Number Line Tool

INTERACTIVE: Ratio Table Tool

Reflect On Your Work

Work Time

Reflection

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

Percents greater than 100% are useful because …