Module 4

Module 4: Area

Explore

The square-foot piece of newspaper you used for TT 1 and TT 2 is an excellent referent. You can envision the area of 1 ft2 more easily now because of it. You have been using referents in many of the past lessons, and now the focus is on the use of referents to estimate areas.

Self-Check

SC 1. What referents do you use for the units of measures shown in the following table? Two common referents for the square inch are given as an example. Make sure your referents are accurate. Be sure to measure!

When you have completed the table, check your answers against some sample referents.

Compare your answers.

© AKaiser/shutterstock

In the next activity you will test your skill in estimating areas using SI and imperial units.

Before you begin estimating, consider which units would be the best to use to measure the different areas. Often, the most appropriate units allow for small whole numbers to be used in the measurement.

For example, the book cover in the picture has an area of 99 in2. This area is also equal to 0.076 yd2—not a whole number of square yards. You would sound a little strange saying the area of the book cover is 0.000 016 ac! Not only would it be strange, but it would also be hard to visualize the size as a small fraction of an acre. So, why might you think a square inch is the best unit for measuring the area of this book?

A good choice of units allows for small whole numbers to be used in the measurement. By choosing inches, you can express the area measurement as 99 in2.

Think of your bedroom. Would it be appropriate to express the area of your bedroom in square inches? What would be a more appropriate imperial unit?

Do you remember what SI stands for?

Would it be appropriate to express the area of your bedroom in square centimetres? What would be a more appropriate SI unit?

Try This

Work with a partner, if possible.

TT 3. Complete “Estimating Area Using SI and Imperial Units.”

Share

Compare the units and measurements you used in your table from TT 3. With a partner or in a group, discuss the following questions:

• Did some units cause the measurements to be very large or very small values?
  
  
• Which units helped keep the measurement values manageable, reasonably sized whole numbers?

After your discussion of the preceding questions, write a short paragraph. In the paragraph explain how you can find appropriate units to measure the area of an object. Place this paragraph in your course folder for future reference.