Revisit Percentages

Warmup

Activity #1

Calculate Percentage.

In this activity, you are going to calculate the percentage of each color on the segmented bar. follow the instructions below to interact with the applet.

• Calculate the percentage of each color on the segmented bar.
• Enter the value in the appropriate box representing the meal type and click “Check”. You won’t get a feedback if the answer isn’t correct.
• Enter the total value in the box at the end.
• Click “New Order” for another question.

Activity #2

Explore Concepts on Percentage.

In this activity, you are going to use the applet below to review concepts on Percentage. Just follow the instruction below. Close to the end, you will be required to answer some questions.

• Click on the forward arrow in the applet below until the end to review steps applied in finding percentage.

Activity #3

Explore Percentage by Composition.

In this activity you are going to explore the connection between ratio and percentages. Use the applet below to help you solve the problems.

You have mixed 5 liters of pink paint using red and white paint. The mixture is 60% red, but you actually wanted a 5 liters mixture of 80% red. How can you fix this without starting again? You can add more red paint to your mixture.

• Move the red slider slowly to the right to observe how the percentage of red increases as the mixture increases.
• Click on the reset button.
• Now move the white slider slowly to the right to observe how the percentage of red reduces as the mixture increases..

You should have found out that by adding 5 liters of red paint, you get 10 liters of the desired 80% red mixture. However, this wastes 5 liters of paint as you only wanted 5 liters to begin with.

(1.) Find the number of liters of white and red paint in the original 5 liters (60% red to 40% white).

(2.) What is the ratio of red to white paint in its simplest form?

We can’t take white paint out of the mixture, so to get a higher percentage of red paint we need to add red.

• Add (a) 1L (b) 3L (c) 5L of red paint.

(3.) What percentage red paint does each one give?

(4.) Write each of these percentages as a ratio of red to white paint.

(5.) Can you find a less wasteful way to get 5 liters of 80% red paint. (Hint: you need to pour some of the original mixture away first.

Challenge #1

Bottle A contains 4 ounces of water, which is 25% of the amount of water in Bottle B.

(1.) How much water is there in Bottle B?

(2.) Bottle C contains 150% of the water in Bottle B. How much water is there in Bottle C?

(3.) Bottle D contains 12 ounces of water. What percentage of the amount of water in Bottle B is this?

Challenge #2

Priya has completed 9 exam questions. This is 60% of the questions on the exam.

(1.) Write an equation representing this situation. Explain the meaning of any variables you use.

(2.) How many questions are on the exam? Show your reasoning.

Challenge #3