*THE FOLLOWING IS ADAPTED FROM WWW.THURSDAYSCLAsSROOM.COM/09SEP99/TEACH4.HTML
MICRO-MATH: SMALL NUMBERS & MICROBES
“Germs” is what most people call microbes. They may be talking about bacteria, fungi, simple animal-like organisms or even viruses. Germs are small!! Scientists measure microbes by using micrometers (microns) or nanometers. Generally, we use millimeters to measure “small” things, but you learn in this activity that microscopic microbes are ultra- small.
The smallest living microbes on Earth are about 340 nanometers long, but fossil microbes have been found that are only 50 nanometers long. in fact, a Martian meteorite contained what scientists believed to be fossil microbes less than 50 nanometers across.
You will need the numbers in this chart to do the Micro-Math:
1m = 100cm = 1000mm = 1000000mm = 1000000000nm = 10000000000A
1mm = 1000mm = 1000000nm = 10000000A
1mm = 1000nm = 10000A
PROCEDURE/QUESTIONS:
*USING THE MILLIMETER MARKINGS, measure the height of the eraser on your pencil.
1. How many millimeters tall is your pencil eraser? ______________mm
2. How many micrometers tall is your eraser? ____________ mm
(Clue: 1mm = 1000mm)
3. How many nanometers tall is your eraser? ___________ nm
(Clue: 1mm = 1000000nm)
*USING THE MILLIMETER MARKINGS, measure the width of your little fingernail.
4. How many millimeters wide is your little fingernail? ___________________
5. How many micrometers wide is your little fingernail? __________________
6. How many nanometers wide is your little fingernail? __________________
7. How many Angstroms wide is your little fingernail? ___________________
(Clue: 1mm = 10000000A)
*USING THE MILLIMETER MARKINGS, measure the width of a coin.
8. Record the width of the coin in millimeters, micrometers, nanometers, and Angstroms:
_______________ ________________ ________________ _____________
ENRICHMENT:
9. Some bacteria are 1 micrometer long, how many millimeters long are they?
10. A very good light microscope can measure things as small as 0.2mm, how many nanometers is that?
11. A carbon atom is about 1 nanometer wide. Can it fit through a hole that is 15 Angstroms wide? Explain your answer.
12. Explain this sentence: Millimeters are tiny distances, but germs are ultra-tiny.