Lyrics

Chorus
If I need to measure up a clock (circumference)
Measure the post on a dock (circumference)
If I’m buying rims for a car (circumference)
Hey, yo, 2πr! (It just makes sense)
If I need to measure up a hat (circumference)
Spinnin’ records like that (circumference)
If I need to pick the right jar (circumference)
Hey, yo, 2πr! (It just makes sense)

Verse I
Check out and see all the round things you can find
So many circles out there, it will blow your mind
It can be hard to measure distance around
But once you use a little math you can figure it out
If you need to find the distance around a circle shape
All you need is one formula and a measuring tape
Then you measure up the radius so you can figure out
‘Cause twice that radius times π is what a circle’s all about

Chorus

Verse II
You know that every circle—if it’s big or little—
Has one single point that’s right in the middle
So you start on one edge, draw a straight line
Right through the center and to the other side
That’s the diameter. And half of that is the radius
That’s the crucial number that we need to figure this out
Then we multiply it by 2π
Circumference, 2πr, there’s no need to ask why

Resources

Further Reading

Website: Mrs. Glosser’s Math Goodies
Circumference
This website explains circumference and how to calculate it. It also provides practice problems.

Lesson Plans & Activities

Website: The Educator’s Reference Desk
Discovering Pi
This lesson plan teaches students about the function of pi, focusing on circumference and diameter.

Website: Education World: The Educator’s Best Friend
As Easy As Pi!
After conducting a scavenger hunt at home to find circular objects, students use and explain pi and the formula for circumference.

Website: Education World: The Educator’s Best Friend
Plan a Pi Day Party for March 14th
This website has over two dozen activity ideas for celebrating Pi.

Website: Math Forum
Circling Around
By actually measuring various round objects, students enhance their understanding of circumference.

Website: Mrs. Glosser’s Math Goodies
Circumference and Area
This website has links to several circumference activities.

Website: New York Times Learning Network
Pi(e) Anyone?
In this lesson, students use poetry and experimentation to learn about and estimate the value of pi. Then, they use their knowledge about pi to write their own poems on the subject.

Website: The Teacher’s Corner
Floor Circles
By using designs on the classroom floor, this activity helps students to better understand circumference.