Additional Math Pages & Resources

Wednesday, January 27, 2010

How long can you eat?

Yesterday's blog was on calculating the length of your shoelaces, and I went to lunch immediately after finishing it.

As I looked at the spaghetti on my plate, I wondered if I could calculate the length of spaghetti noodles. In fact, how long is the total length of the spaghetti noodles in an average serving?

This requires some facts. So I grabbed a noodle and (lacking a ruler) laid it out on an Excel Math Lesson Sheet.




The noodle is just a bit shorter than an Excel Math Lesson Sheet. That means it's about 14 inches.

I could have dumped the whole plate out on my desk, lined up all the noodles and measured them.  But I was hungry and I kept eating away while I thought about how to figure out the length of a bowlful of spaghetti.

Measuring might have been easier than calculating their length from published sources. It's a bit like the exercise we went through several months ago wondering how many worms are in our worm farm . By the way, the worms are doing well. We moved them indoors for the winter.

Back to the spaghetti. By surfing the Internet I learned:
  • a side serving is 2 ounces by weight; a main serving is about 4 ounces.
  • a side serving is a bundle of (uncooked) noodles about the diameter of a US quarter dollar
  • a serving of cooked pasta is a pile about the size of a tennis ball
  • noodles expand when cooked because they are only 12% moisture before cooking
  • the average American eats about 20 pounds of pasta a year
  • an ounce of pasta is about 100 calories
  • a fine spaghetti noodle is about 1.5-2.5 mm in diameter and 10-12 inches long
Some of these facts came from the pasta manufacturers, and others from the World Food Programme, a United Nations website that is dedicated to ensuring that food supplies are safe, of good quality and can contribute to an acceptable nutritional and health status for all population groups.

Did I learn anything that could help me calculate how long the noodles in a serving would be? Well, I remembered a lesson we did on coins ...




I pulled the graphic off my hard drive. A quarter is about 25 mm in diameter. If we know the diameter of a noodle, maybe I can come up with something... and here it is.

Your own digital pasta noodle comparator. Noodles of 4 diameters, fitted inside a ring the diameter of a quarter. Just choose your noodle size and count the number that fit inside the ring. Multiply by 4 to get the whole set of noodles that will fit.



You could do it with math too, without this fitting process. But it would take more than elementary level math, so we'll leave it for another time.