First, this activity will take about 20 minutes.
Show the students the problem and make sure they know what is being asked. Don't give any clues as to how to solve it. Have them work in pairs to come up with a plan to solve it.
After about 3-5 minutes pick a pair at random to explain their plan. A class discussion will take place on the plan. Then that pair will start executing the plan and all in the class will do the math for that plan. Plans have differed from class to class. But, they will definitely need to use the Pythagorean Theorem to get the answer.
The students solution: Usually it will be to measure two sides with the ruler, and then find the third side using the Pythagorean Theorem. They now have the 3 sides in centimeters. Then they measure the key in centimeters. They sometimes use a proportion to convert the centimeters to miles.
It is great fun to watch the student trying to use the ruler on the IWB to measure. The students are using collaboration, problem solving, and math skills with this activity.
Hope you can try something like this in your class,
Dave
Thank you for posting this exercise. I follow your blog, but this one just recently stuck out to me. I am redesigning my geometry units and used map problems in 2 unit so far. The first was for segments addition, so I used 3 collinear cities. I used the same map for the 2nd lesson on distance. Your blog turned a light on for me to extend the same pic into Pythagorean Theorem!
ReplyDeleteThanks again,
Tori
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