## Tuesday, December 6, 2011

### A Measuring Quandry

We've been having a lot of fun in my math group so far this week, exploring the ways our bodies can be used as measuring tools. Yesterday, we learned about the historical significance of a "foot" or "ruler", and traced our own feet on pieces of construction paper. We also made a different kind of ruler - using the width of of thumbs for each "inch". We noticed that only my thumb, an adult thumb, was almost exactly the same width as an actual inch. The children excitedly compared their foot ruler and thumb ruler.

 Making a ruler from a foot

 And some thumbs
Today, we extended this to learn about other types of body measures - the span, yard, fathom, and cubit. I asked for a couple of volunteers to demonstrate measuring each other using a cubit (from elbow to fingertips). Clementine measured Ariana and then Ariana measured Clementine. Oddly, Clementine seemed to measure taller than Ariana, even though the students could clearly see that Ariana was taller. Someone mentioned that perhaps one had shoes on, so both girls took shoes off and tried again. Same results! Another child thought that maybe one child was not standing quite straight, or one was bending their arm. Another demonstration, but it still was clear that Clementine was somehow measuring taller than Ariana. Finally, Maddy said, "Oh! I know! Clementine's cubit is smaller than Ariana's cubit!" And, indeed, the math mystery was solved. Partners then helped each other cut a piece of yarn one cubit long, and measured different items around the classroom.

 Different children, different sized cubits!

 "Look! This poster is exactly one Noah cubit long!"

#### 1 comment:

Angela said...

Leo told me why a ruler is called a ruler and why it is 12 inches long. Thank you Mrs. C for making math extra FUN!