“Wouldn’t it be great if we had a carpet in our classroom? ” I asked my students, “A rug where we could all sit together and share ideas, where we could stretch out and read stories?”
This initial idea sparked a practical mathematical investigation in our classroom as Dani, Mike, George and Constantinos collaborated to solve the problem. I asked them to figure out the following:
About how much carpet area is needed for twenty children and one teacher to be able to sit around the edges.
• What are all the possible dimensions of such a rug?
• What options are best and why?
• How much would this cost to buy at IKEA?
“Let’s measure how much space an average 5th grader needs to sit,” said Mike. “Let’s measure George and Constantinos.”
“Don’t forget the teacher! We can measure the chair for her and add that in,” pointed out Constantinos. “It’s about 70 cm.”
“Ok, if 1 5th grader needs 60 cm, then 20 students will need 1,200cm, plus the teacher’s chair equals about 1,270cm. If that is the perimeter, then we can have either a rug 500×135, or 400×235. “ figured Dani.
“Let’s see which would fit best in the corner by the cubbies,” said George thinking practically.
“The second one is better because the first would not fit. It would go on the wall,” figured Dani.
“Mrs Kynigou told us the cheapest rug costs 19.99€, but it’s not big enough. It’s only 133x197cm. Two rugs fit almost everyone, but it’s not fair to leave some kids sitting on the floor. Can we buy three?” they all reasoned.
“If we have three rugs 197×399, then the perimeter is 1,191cm. That is still not enough. I think I have a better way…like an L shape…That gives us 1,320cm, that’s enough for 20 kids,” argued Dani.
The students took their finished reports and shared them with Ms Makropoulos. They came back excitedly, “The principal agreed! Now we have to find out if the other fifth grades want rugs too?”
“Wait! How much will that cost?”
“She told us to fill out a requisition. What’s one of those and how do you fill it out?”
We are all eagerly awaiting the arrival of our “magic carpet”!
“We’d better hurry up,” says Dani. “That offer only lasts until the end of November!”
Posted by Mrs Kynigou
What math skills did our students use to solve this problem?
Write a comment below identifying a specific skill used to solve a specific part of this problem.
Can you suggest another real life project that we could try to solve using our math skills?