Comment by hathawsh
2 years ago
I remember the glee I felt when I first used logarithms to represent large numbers in Excel. Suddenly, I could easily approximate large factorials, and they were fast! I wondered how many other people have discovered this trick. I couldn't find many references on the Internet. Over time, I realized this method of handling large numbers is used so often that most people who know about it don't bother to talk about it.
This should have been part of the HS curriculum.
Logarithms pop up (IIRC) in 10th grade, and ln(x*y) = ln(x) + ln(y) is usually explained as part of that. What many teachers completely fail to teach is that it's not just a formula to memorize, but that it has profound implications on how you can do math. As you discovered by yourself. (Kudos!)
It is, with the right teacher, a super-exciting story with lots of colorful history & characters. You can even guide your students to come to that some crucial insight. Alas, few teachers have the necessary amount of passion to make that come alive.
But that's probably why few people write about it - for most, either their math interest got murdered in HS so they never get to look at it, or they did learn it in 10th grade and so consider it not worth mentioning.
(Corollary - we all should write more about the cool realizations we had, even if they're in retrospective "well known")