Increasing and Decreasing Percents Assessment

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Objective

SWBAT interpret percent increase and decrease.

Big Idea

How do you apply fractions and decimals to percents of change?

Launch

10 minutes
  • POD

As students enter the room, they will have a seat, take out their Problem of the Day (POD) sheet and begin to work on the question on the SMARTboard. The POD allows students to use MP 3 continually based on the discussions we have about the problem each day.

Our POD today asks students to find a percent of change however they feel most comfortable. I want to see if any of the students depend on the bar diagram, the ratios, or an algorithm with fractions or decimals. As we talk through the solution to the problem I want students to discuss why they chose the problem solving method they did. If none of the other options are chosen, we can solve using another method as a group and talk about the “best” way to find the answer. What makes it the best way?

Find the percent of change. Round to the nearest whole percent. State whether the percent of the change is an increase or a decrease.

48 notebooks to 14 notebooks

$240 to $320

Explore

20 minutes

We have used ratios and proportional reasoning to find percents of change. Students started with bar diagrams, giving them a concrete visualization of the concept as a foundation. We moved to ratios to build upon conceptual understanding that students have to help them find the changes. Today’s lesson will guide students through finding the percent of change using fractions and decimals as part of the algorithm. Students will understand how to apply a fraction or decimal to an amount and determine the amount or percent of change.

We will start this mini unit with the Percent Changes assessment, included on page S-1 of the MAP lesson that will give me an indication of what students understand about using an algorithm to solve problems. I don’t want them to use the strategies we have used in past lessons but rather use the calculator to establish a problem-solving method. Are they able to determine what happens when finding the percent change? Can they apply that knowledge using a calculator? Are they reliant upon the proportional reasoning to find the solution or can they use fractions and decimals? They do not have to find the actual solution, but create the key sequence for solving the problem. After students complete the assessment, we will not go over the answers. This will also be used as a post-assessment. 

Landing

10 minutes

The exit ticket for today will just ask students to gauge their own comfort level with using a fraction or decimal to find the percent of change. This is a step away from the work we have done to this point with percents so I want to know how students are feeling before we move on.

EXIT TICKET

Can you find the percent of change using a fraction or a decimal? Explain to me how to do it.