I went to the store with my wife today to find a snack, and ran across a bag of cheese puffs called Smart Puffs, and the bag design caught my attention.

That Sigma notation in the middle is incorrectly formed. But seeing it today reminded me of the first time I saw it in my second semester of Calculus. As a Computer Scientist, summation made perfect sense to me. It is, in essence, a for loop:

What you are saying with that Σ is to sum all i‘s from 1 to 100 (or whatever is on top), as I have shown before when finding sums in C++. An exact analog to a loop. Here’s a better graphic explaining summation:

As you can see, summation is just a fancy way of writing a long string of addition. It doesn’t make a lot of sense to use a Σ for this small example, but when the top number goes out past 100 (or like the ones in Calculus that increase without bound) it’s much more practical to write it as a summation formula. I made a couple corrections to the image from before; I only hope someone from Pirate Brands notices this article and changes their bag accordingly.

~Jonathan

Jonathan Landrum is a full-time husband and student, and a part-time research assistant and IT guy. He both works and studies at Mississippi College, where he is pursuing a Bachelor of Science in Computer Science. Continue reading…