Cut-and-Paste Pi: Pi Post #3
January 17, 2014
Here’s a hands-on, cut-n-paste paper project that, hopefully, puts pi in your hands. This post is 19 photographs long, so, in deference to anyone to whom seeing that circumference divided by diameter equals 3.14 is inconsequential, I have hidden the bulk of this post under the MORE tag button in this post. If you want to see the whole project, please click the more button, and I will see you on the other side….
1. Here I’m laying my big roll of silver tape on a line of the paper and marking the lowermost point.
2. Next, the top of circle gets marked. It so happens that this mark lands on a line, but this won’t always be the case!
3. Use the rule to make lines across the paper to show the distance between the points. The lower point, which was on a line to start with, will be easy to draw. If the top point didn’t land on a line, lay the ruler on the point and eyeball the ruler so that it is parallel to the lines of the paper. This is easier than it sounds. You’ve now delineated across the page length of the diameter of the circle.
4. Crayon in four strips of color between the drawn lines.
7. Paste or tape the second strip on to the cylinder, making sure that it is right next to the end of the first strip.
8. Paste or tape the third strip onto the cylinder, again making sure that this strip is exactly lined up with the end of the previous strip.
9. After gluing down the three strips around the cylinder, notice that there is a small gap between the first and last strips. This is a .14, or 14%, length of the diameter that we started with. Now, get ready to make .14 of the original diameter:
11. Fold it in half, and you have .50 of the diameter.
12. Fold in half again and you’ve got .25 of the diameter.
13. Here I’ve cut off the .25 diameter piece so its easier to work with. Fold this in half and….
. 14, so,…
The piece I’ve just cut is acceptably close to .14 of the diameter, which I can prove by fitting it into the space between the strips that are already glued on to my cylinder.
And there it is! it took 3.14 diameters to surround the cylinder.
If you have made it all the way to the end of this post, please let me know what you think. Thank you!!