Math In Action

January 01, 1996 1 min read

If you think you don’t have any use for algebra, think again. Here are some everyday problems from the Interactive Mathematics Program.

Sprained Star

A star basketball player suffered a sprained knee a month before the playoffs. The team’s general manager must decide whether to gamble that the player will be healthy enough to compete in the playoffs or whether he should put the team member on the disabled list, enabling him to sign an athlete of lesser ability. An athlete is considered capable of playing when his quadricep measures 250 foot-pounds on a strength test. The day of his injury, his injured leg measured only 55 foot-pounds. Using the doctor’s reports, which show how the athlete’s strength is increasing, graph the player’s progress and project whether he will be fit for the playoffs.


Ben frames photographs using pieces of framing material cut from long strips. After framing the photo, he also treats the visible part with a clear liquid so it won’t fade. Ben charges 25 cents for each inch-length of framing material, plus 50 cents for each square inch of photo that he treats. Write a formula that will tell Ben how much to charge for framing and treating photos.

Everyone’s Got An Angle

An eye surgeon must perform an operation on a person who has pressure behind the cornea. The surgeon will use a laser to make small holes along the edge of the cornea. The patient will be lying on the operating table, and the laser will be directly above her pupil. The laser is 45 millimeters from the outer edge of the cornea. The diameter of her cornea is 10 mm. The surgeon needs to find the angle at which to set the laser. Set up an equation that could be used to find this angle.

A version of this article appeared in the January 01, 1996 edition of Teacher as Math In Action