From: Ron (for Teacher2Teacher Service)
Date: Jan 31, 2001 at 05:25:59
Subject: Re: Percentages

When I teach this topic I bring in a newspaper and have the students look at
the percent type questions in the paper. This is a more "real-time activity"
than getting the question out of the text book. Each group of students picks
an example of their choice and discusses it with the class. I try to
influence their choices so that a wide range of applications are presented.
For example:
sales, discount, interest charges, bank charges, sales tax, percentages used
on the sports page, percentage increase.

To answer your specific question:
Original Price * Percent Off (expressed as a decimal) = Discount
Original Price - Discount = Sales Price

Have the students work on getting a one-step solution to this type of
problem:
Original Price * (1 - percent off (expressed as a decimal)) = sales price

Using your example:
Two-step solution:
Original Price * .30 = Discount
Original Price - .3 * Orginal Price = 84.00

.7 * Original Price = 84.00    --------  One step solution
Original Price = 84.00/.7
The original price was $120

Hope this answers your question.
Cheers.

 -Ron, for the T2T service

Post a public discussion message
Ask Teacher2Teacher a new question