Lesson: Bionic Beasts

Provide students with a proportional scenario that includes all four parts of the proportion. For example, tell students that for a batch of cookies, a recipe requires 3 cups of flour and 2 eggs. Making five batches of the cookies requires 15 cups of flour and 10 eggs. Show students the multiple ways they can write a proportion using these four parts, and start a discussion about how the units in each proportion help to ensure accuracy.

Display or digitally distribute the “Engineering Design Process” template. Discuss each step and the questions used to guide the process as a class. Ask students to look for examples of the engineering design process in the video they are about to watch. Then play the video and have students fill out their template. Hold a class discussion about where they saw examples of the engineering design process. (Possible examples: 1. Derby was born with deformed front legs and needs an invention to help him move; 2. The owner attached a cart with wheels to Derby to help him move; 3. The cart limited Derby’s ability to play with other dogs; it also didn’t enable Derby to use his full range of motion.)

Have students read the article in pairs. Then ask the following discussion questions:

• What are prostheses? (Prostheses are artificial devices that replace missing body parts.)

• How did Derrick Campana get into the animal prosthetic business? (Campana made prosthetic limbs for humans. A veterinarian approached him about making a prosthetic leg for a dog. Since then, Campana has been making prostheses for animals.)

• What is a challenge for Campana in his work? (Since Campana often never meets his clients and doesn’t see the prosthesis on the client, it is hard to fix a prosthesis that doesn’t fit or work quite right.)

• What is Campana’s favorite part of his job? (Fitting the prosthesis on the patient—he loves seeing his patients happy and mobile)

Play the instructional math video for students before reading the Skill Spotlight. Pause the video at 1:40 to re-explain how to cross-multiply using the numbers provided in the example and allow students to ask any questions they might have. Then play the remainder of the video.

Read the introduction and the example of the “Finding Proportions” box on page 10 aloud. Point out to students that the example shows a different way to solve the proportion than the video did. Notice that, in the example, the variable is in the numerator. Tell students that if the variable is in the numerator, they can solve the proportion in the same way as the example—it doesn’t require cross-multiplication. Since the variable is in the numerator, it is easier to isolate the variable. Have students work in pairs to answer the “Your Turn” questions. Then invite volunteers to show the class how they set up their proportions to solve the questions.

Tell students to imagine they are about to get a new pet and choose one. Have them design a floor plan for the pet’s room, using a ruler to measure its different dimensions. Then have them use proportions to determine the actual measurements of the room. Tell students to include one real-life measurement, such as: The play area is 6 feet long.