## Pricing Mistakes Challenge

I challenged my students this week to find pricing mistakes. For example, mistakes such as .11¢ instead of \$0.11 or 11¢.  I found two of my own this week.  Here they are: See the full gallery on Posterous ...

## Scotch Tape and Gas Prices Dilemma

So, my whole recent obsession with Scotch Tape sort of began a few weeks ago when the following problem popped into my mind... Suppose your boss wants you to buy six 1/2 in x 450 in rolls of Scotch tape at the dollar store (remember the 6% Michigan sales tax).  Your boss wants you to use the tape to enclose an area of 3,225.8 square cm, but has only given you a budget of \$7.00 to do so, including the amount of gas to drive back and forth to the dollar store, which is exactly 1.5 miles away from work.  Your car gets 0.0735 liters per kilometer city (you will not be taking the highway), gas is \$4.09 per gallon, and your boss does not care about the gas that it takes to actually start your car.  Do you have enough tape to enclose the area that your boss asked to have enclosed?  If you do have...

## #anyqs Related ‘Stuff’

If you're not familiar with #anyqs, start here: http://blog.mrmeyer.com/?p=10120.  Otherwise, enjoy. ...

## Rotten Tomatoes, Linear Equations, Ratio and Proportion

This problem came about because I was talking about solving the equation 4x + y = - 14 for y and there was a little confusion about how I could  subtract 4x from - 14.  Although this was really a problem with combining like terms, I figured that now was as good of a time as ever to reinforce the idea of combining like terms. "Yaletta bought an unknown number of tomatoes at \$4 each, but when she got home, she found out that all of the tomatoes were rotten.  In addition, she checked her receipt and realized that the store had charged \$14 to carry the tomatoes to the car.  Write an equation to model Yaletta's total losses." (as a signed number) The students seemed to come to the consensus that an appropriate answer would be y = - 4x - 14. Then I asked these questions as well: What does y represent? What does x represent? What does -4 mean? What...