Conjecturing with Logarithms
by Marsha Hurwitz, Duchesne Academy, Houston, TX 77024
in the January 1991 issue of The Mathematics Teacher
After giving students the definition of a logarithm,
divide the class into pairs or groups of three.
Each group is given two envelopes containing several
index cards (Four sets of sample cards appear below).
Each group is given about three minutes to make correct
mathematical statements using the cards in the envelopes.
Not all cards in the envelope are used in the equation.
At a signal, a spokesperson for each group reads the equations
and I write them on the chalkboard, grouping similar equations
together.
The students then try to formulate a general statement that
summarizes the pattern found in the groups of similar questions.
We write these conjectures above each group:
Here is a set of sample cards:
