You and Your Students!
Vicki Cobb, Education World Science Editor
You can tell a person's shoe size without looking at his or her foot!
Human Body, Measurement
Setting the Scene (Background)
Measurement is an important part of science, but try to teach measurement and you often hear groans from students. In these easy- and fun-to-teach activities, the human body offers some surprising proportions that can ease you into the subject.
Use a ruler or a piece of string to measure the distance from the elbow to the wrist. Then measure the length of the foot. (Flexible kids can put a bare foot against their forearm with the heel at the elbow.) What do students learn? (Surprise! Both measurements are the same length!)
The body has some other surprising proportions:
The human body has served as a measuring stick for centuries because it is a portable measuring device. Over history, the first knuckle of the thumb was equated to an inch, the length of a foot was equated to the measurement of the same name, the distance from the fingertip of an outstretched arm to the tip of the nose was equated to a yard, and the width of the palm is the four-inch "hand," which is used for measuring the height of horses.
How reliable is the human body when it comes to measuring other some other variables? Not very! Here are some things you can try:
Measurement is a way of knowing what's real. Ren Descartes (1596-1650), the French mathematician and philosopher, concluded that trusting your senses was not the way to know reality. What do your students think on this subject? Why is it important to have measurement standards?