Biology: How small is small?

This week we learned a technique for measuring specimens under the microscope. The kids measured the lengths of ants and even actual cells. You can be sure we weren't measuring in meters or even centimeters. The kids got some practice with micrometers, 1000 of which make a millimeter.

How did we do this? Using a ruler, the kids measured the field of view. Then they converted this number to micrometers (so much easier to work with when you're measuring cells and such). They estimated how many times a specimen would fit within the field of view, did some simple math and came up with a measurement that was within 100 micrometers (.1mm of the accepted answer). Not bad for a day's work!