How Does Your Body Measure Up?

How tall are you?
Find out by spreading your arms out as wide as they'll go and have your partner measure the distance from fingertip to fingertip.

Not quite as accurate, but did you know that your are as tall as 2 - 3 times the circumference of your head?

How big is your foot?
It's the same size as the distance from your wrist to your elbow!

You can also find out how big your foot is by measuring the circumference of your closed fist!

Left your ruler home and need to know how big an inch is?
It's about the distance from the tip of your thumb to the first knuckle

Need a yard of burlap for that Halloween costume and don't have a yardstick?
No worries. Just stretch your arm out as far as it will go and measure from the tip of your finger to the tip of your nose!

Need something to measure more than an inch and less than a foot?

Just use the width of your hand. Across the knuckles it measures about 4 inches..

Some of these measurements don't work for you?
Two probable reasons:

  • First, you're probably a kid and still growing. Wait a few years and try again. In the meantime, you can annoy all the adults you know by taking their measurements and seeing how accurate this is.


  • Second, this is just a "rule of thumb." It's reasonably accurate just enough that it's useful. It illustrates the reason we don't use such non-standard units of measurement for anything that matters.
Have class work in pairs and measure their bodies.

Collect data and discuss - e.g., for 95% of class the distance from the elbow to the wrist equals the length of the foot within 1 inch.