Percentages

Lesson

- To practice operations with fractions in real life.
- To explore how percent change can be applied to a real life situation.

- Wooden Blocks
- Measuring tape
- Paper
- Pen

Work with a partner or small group for this investigation.

- Use the measuring tape to measure the length, width, and height of one single wooden block. Record these measurements as fractions.
- Make a guess as to how tall you think the wooden tower will be and how wide it will be. Be sure that your answers are in the form of a fraction or a mixed number.
- Build the wooden tower.
- Measure the height and width of the tower using the measuring tape.

- How close was your guess to the actual height of the tower?
- How close was your guess to the actual width of the tower?
- Begin taking turns removing blocks from different parts of the tower and placing them on top of the tower.
- After 5 blocks have been placed on the top of the tower determine how the height of the tower has changed and write your answer in terms of a mixed number or fraction. Do not re-measure the tower.
- Continue taking turns removing blocks from the tower and adding them to the top. After doing this a few times again determine how the height of the tower has changed and write your answer in terms of a mixed number or fraction. Do not re-measure the tower.
- How high would the tower be if you increased the original height of the tower by $20%$20%? Is it possible for the tower to reach this height and still stand? Explain your answer.
- How high would the tower be if you increased the original height of the tower by $40%$40%? Is it possible for the tower to reach this height and still stand? Explain.
- Compare and contrast you answers for numbers 6 and 7 as well as the methods you used to find those answers with another group.
- If you said that the tower can be built up to $20%$20% its original height, build it. Were you right?
- If you said that the tower can be built up to $40%$40% its original height, build it. Were you right?

Understand operations on fractions, decimals, percentages, and integers