8. Logarithmic Functions

8.1 Understanding Logarithms

Class Notes

The McGraw-Hill Ryerson PreCalculus 12 Text is used as the Main Resource.

Assignments in the Powerpoint Lesson Plans refer to pages and questions in the PreCalculus 12 text.


 8.1 Understanding Logarithms (revised)

 

Digital Resources to Engage Students and Differentiate Instruction

 What is a Log

 

Watch the video to Graph inverse function x = 2^y: Introducing%20Logs%20as%20the%20Inverse%20of%20an%20Exponential%20Graph.wmv

Pedagogical Shifts: TRANSFORM, Moving from Traditional to Student-Centered

Have you ever played the card game WAR? It's a game where two players divide a deck of cards between them. Each player flips up a card. The player with the higher value card takes both cards and adds to their deck. The process is repeated again and again. The player who collects all of the cards has won the game. Do you remember what to do when the values are the same... a "tie"?

Log Wars in action

Here is a version of the game called Logarithm War Activity.

The activity includes 4 pages of benchmark logarithms similar to the picture below. I copied the pages on thicker coloured paper and then used a paper cutter to cut up the cards and placed them in an envelope. Students were randomly grouped in pairs and played war with logarithms.

Log War Activity 

I was impressed at the students' ability to use Mental Math and Estimation to evaluate the benchmark logarithms. They played war for about 15 to 20 minutes during class. Students were very motivated to understand every single example. I found it interesting that after playing for a while, students separated the cards into expressions that they knew and expressions that the did not understand. They also grouped expressions that were similar.... argument of 1. When they called me over their comment to was was " I get these, but I don't know how to do these?" This made me realize that the Logarithm Was Activity was a good example of TRANSFORM and Pedagogical shifts from Summative Assessment to  Formative Assessment .

 

Logarithms: Line them Up!

In this activity, I used the Logarithm War expressions and wrote them on individual sheets of paper. I randomly distributed the expressions to the students. Students were asked to line up in ascending order using the value of the expression.... without talking. Students in the "gallery" had to decide if the values were in the correct order. There was an interesting discussion about log(0) and log(-4) and where they should be in the line-up. I also included some examples such as logb(b^4). This was a nice activity that promoted communication and mental math and estimation.