Tactile math (chalk and string and a little bi-secting)

I loved the kids enthusiasm about our latest out of class math lesson- come rain or shine!

As we are learning about Ancient Greece, I decided to do as the ancients did. Using only sting and chalk, students worked on their own, trying to figure out how to bisect line segments, create perpendicular lines and parallel lines. In their first attempt, many simply used guess work to find parallel lines; in a second attempt we went through three basic steps:

1. create a straight line by holding the string down at point A and B and tracing the chalk along it.
2. bisect the line by folding the string in half to find the midpoint
3. Extend the string to its full length again and place one end on point A. Draw a semi-circle from the midpoint in a rainbow/ arch above the line. Do the same from point B.
4. If you have done this correctly, you will have creates an X which is perpendicular to line segment AB if you connect X to the midpoint.

 

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