Ever hear a student ask the question, “Where am I going to use this in real-life?” This 4-page activity (plus two pages of answer keys) employs a real life application of the multiplication and division of fractions, in keeping with the common core standards.
I have designed it to support a unit entitled “Archimedes – the Mathematics of Ancient War.” In that unit I explore a bit of the history of Archimedes and highlight some of his major contributions, like his work with pulleys, and move into his utilization of mathematics to create weaponry that was cutting edge in his day.
This activity, The Power of Pulleys, briefly explores the results of Archimedes work with pulleys, demonstrating how different configurations of pulleys can reduce the force needed to lift objects. Along the way, the concept of fraction multiplication is applied.
Example: Given a certain pulley configuration the amount of Pull (P) needed to lift an object weighing (W) 200 lbs is written as P = (1/2)W, or P = (1/2)*200 lbs. Therefore, it would take 100 lbs of pull to lift the object.