From: Claudia (for Teacher2Teacher Service)
Date: Apr 03, 2000 at 16:43:43
Subject: Re: Logarithmic functions

How did you start?  I usually start by simply showing the students that the
only thing a log is ...is an exponent.  log (2) 8 =  ?  What power
(exponent) do I raise 2 to in order to have an 8????

We do lots of examples like this....then I even do numbers where I have them
estimate.  For example,  log (2) 17 = ?  2 to what power = 17???  since 2^4
= 16, the log is just a little bigger than 4.  Have them guess a number?
4.01?  Then we use the change of base rule and enter ln 17/ln 2 or log
17/log 2 on calculators and see how close they come.  After they have done
all of this, we tackle the more theoretical problems and laws of exponents.
Have them take it back to basic algebra.  log (b) (xy) = log (b)x + log(b)y
What do I do when I MULTIPLY like bases?  "Add the exponents"....that is why
we add here !!!!

Hope this helps

 -Claudia, for the Teacher2Teacher service

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