Monday, February 7, 2011

The Loop for Logs

A few years ago, when I was introducing logs, I drew some arrows like this:

I wanted to show that this base here goes with this exponent over there which goes with this answer over here . . .

Then I noticed one of my students drawing a loop on all of his papers, like this:

He said it helped him remember the order, especially for when one of the terms was a variable.  This has turned out to be a pretty helpful mnemonic device for changing logs to exponential form.

This year, when my calc students (who were also in my algebra 2 class) encountered a log, I just reminded them of the loop and they were like "Oh yeah, the loop."


  1. I used this same "loop" with my Alg 2 class, except I drew the arrows in blue (bottom) and red (top) so that it looked similar to the Pepsi logo. They LOVED it and any time they encountered a log would ask, "Can we use the Pepsi method on it?"

  2. Hi. I'm a student who is preparing to be a math teacher. Your blog has lots of useful and helpful information for math teachers. Thank you for your posting! Many students have trouble in understanding log and exponential. I think this "loop method" can help me to explain log and exponential very easily and clearly.

  3. I call it the snail and add antenae and a happy face.