Understanding Percent Change

Understanding Percent Change

Reason Abstractly and Quantitatively

Opening

Reason Abstractly and Quantitatively

In this activity, there are four amounts of money and a set of arrows with different percent increases or percent decreases. Your job will be to place the arrows with the correct increase and decrease between each stack of money.

Discuss the following with your classmates.

  • Can you find two dollar amounts that have a 25% increase between them?
  • Do you think you'll be able to find the correct increase and decrease values for each arrow on the money board?

Math Mission

Opening

Relate percent increase and decrease to decimal and fraction multipliers.

Show Increases and Decreases

Work Time

Show Increases and Decreases

Using the Money Card Sort interactive, place the increase and decrease arrows, which contain percent, decimal, and fraction values, between the monetary values to indicate the correct increase or decrease between the amounts of money. The arrows should be placed both horizontally and vertically.

INTERACTIVE: Money Card Sort

Prepare a Presentation

Work Time

Prepare a Presentation

Be prepared to show and justify your placement of the arrows.

Challenge Problem

Find the percent change and decimal multiplier values that lie between the diagonals $150/$160 and $100/$200.

INTERACTIVE: Money Card Sort 2

Make Connections

Performance Task

Ways of Thinking: Make Connections

Take notes about your classmates’ explanations of their placement of the arrows.

Hint:

As your classmates present, ask questions such as:

  • How did you figure out the percent change between those two amounts of money?
  • Why did you place the arrow in that position?
  • Why aren’t the percent increase and the percent decrease values the same?
  • How did you determine which fraction multiplier was the same as that percent change?
  • How did you determine which decimal multiplier was the same as that percent change?

Percent Increase and Decrease

Formative Assessment

Summary of the Math: Percent Increase and Decrease

Write a summary about using percent increase and decrease—as well as decimal and fraction multipliers—to show increases and decreases in quantities.

Hint:

Check your summary.

  • Do you explain how to calculate a percent increase and a percent decrease?
  • Do you explain how you can represent percent increase and decrease using decimal and fraction multipliers?

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.

I think percents, decimals, and fractions are connected in this way …