Exponential functions
80 ExpMult This program presents multiplication of expressions containing exponents raised to a power. Powers greater than 3 must be represented with the [^] key. The exercises also include manipulating parentheses with exponents. Most classes will probably complete this program and the next, ExpDivid, in one 90-minute session..
81 ExpDivid This program presents division of expressions containing exponents. Answers must be installed without multiplication or division symbols (*,/). Point out that A^0 is not in simplest form. The exercises include operations with negative exponents. They are not difficult and can be completed in much less time than a class period.
82 ExpGrow The exponential growth and decay problems depend on the students' understanding that if a quantity increases by 5% then the factor by which it has increased is 1.05. In order to avoid tedious trial and error, the fourth problem of the set requires that the students understand that the exponent to which a quantity must be raised can be found by taking the log. This is not an algebra 1 topic, but it not too difficult to show the students why the solution is simply
log(fraction remembered after n years) / log(fraction remembered after one year).
Once the principles are grasped, students will complete the exercises in much less than a class period.
83 ExpSciNo The purpose of the scientific notation program is to illustrate how convenient scientific notation can be when one is trying to arrive at approximate answers to fairly complex problems without the aid of a calculator. This is a good opportunity to stress the distinction between precision and accuracy. The program is looking for a precision of only two significant digits in the simpler questions, and only one in the more complex questions. The order of magnitude is what is stressed. The program does not keep track of wrong answers. Everyone who finishes is credited with 100. Encourage the students to make reasonable approximations and do the calculations in their heads. As an example of scientific notation using the EE key, the number of seconds in a minute is 6.0 E1.