 Question

# EXTENSION ACTIVITY: SIZE, SCALE, AND PROPORTION: HOW BIG IS A VIRUS...

EXTENSION ACTIVITY: SIZE, SCALE, AND PROPORTION: HOW BIG IS A VIRUS ANYWAY?

Instructions: Click on the "Show Relative Sizes of the Viruses" tab at the bottom of the interactive home

page. Answer the questions below in the spaces provided. (You will need a calculator for some items.)

1. Using the white scale bar provided, approximately how long (tall) is TMV?

2. What is the approximate diameter of HIV?

3. What is the approximate diameter of Zika virus?

4. So, how big is a nanometer? Study the sample problem provided and then answer Questions 5-10,

showing your work in the space provided for each.

Sample Problem

An average small paperclip measures 3.0 cm in length.

Calculate the length of the paperclip in millimeters, micrometers, and nanometers.

a. Millimeters (mm)? 30 mm

Since there are 10 mm in a centimeter, the calculation is completed in the following way:

3.0 cm x 10 mm/1 cm = 30/1 = 30 mm

b. Micrometers (µm)? 30,000 µm

Since there are 1000 µm in a millimeter, the calculation is completed in the following way:

30 mm x 1000 µm/1 mm = 30,000 µm

c. Nanometers (nm)? 30,000,000 nm

Since there are 1000 nm in a micrometer (µm), the calculation is completed in the following

way: 30,000 µm x 1000 nm/1 µm = 30,000,000 nm

So, a small paperclip measures 3.0 cm in length, or you can say it measures 30,000,000 nm in

length!

5. A single grain of salt measures 0.5 mm in width.

a. What is the width in micrometers (µm)? (Show your work.)

b. In nanometers (nm)? (Show your work.)