Friday, March 16, 2012

The Language of Math... and National π Day

For those of us that teach elementary school, we might have missed the celebration this week.  No, I’m not talking about the NCAA play –in games in Dayton Tuesday night.  I’m talking about the festivities on March 14th – otherwise known as National π (Pi) Day.  You may remember from algebra that pi is the ratio between a circle’s circumference and its diameter.  It is also a crucial part of many math equations.  For example, the area of a
circle is equivalent to pi times the radius squared.  Pi is an irrational and never-ending number, but it is typically truncated to 3.14.  And for the last several years, math teachers across the country have used March 14th (3-14) as a day to highlight the unusual number.  It’s the upper grades version of One Hundredth Day

As you may have guessed from my recent post about Groundhog Day, I have a special affinity for goofy holidays.  As far as I am concerned, I am happy to use whatever resources I can to motivate students to learn.  So, Pi Day is right up my alley.  Oh, the possibilities!  A quick internet search uncovered a number of sites that teachers could use to celebrate this unique number.  There is the Exploratorium’s Pi Day website with live, online and Second Life celebrations and another Pi Day website that offers Happy Pi Day ecards you can send to your friends. 

But if you teach ELLs, you can also use this opportunity to explore the language of math.  Often in my workshops, I write a short math equation on the board. Then I ask participants to turn to their partner and tell them several different ways to say that number sentence.  After a minute or two, I ask for responses and write them on the board.  In honor of Pi Day, let’s use the circled formula in the picture above.  How do you say  A=πr² ? Here are just a few of the possible responses. 
·         The area of circle is equivalent to pi times the radius squared.
·         Area equals pi times the radius squared.
·         Area is pi multiplied by the radius squared.
·         You can find the area of a circle by multiplying pi and the radius squared.
·         You get the area of a circle when you times pi by the radius squared.

Each of these is a perfectly acceptable way to express the math equation.  Some use more social language than others (e.g. you get, you can find, times) and all of them use some specific and technical language of math (e.g. radius, area, squared).  As teachers of ELLs we need to be conscious of our speech.  We need to be deliberate in what we say when we say it.  If we use the statements above interchangeably without highlighting the different terms, we may confuse our ELLs unnecessarily.  So, this week pay attention to what you say in one of your classes.  Do you say the same thing (e.g. 5-3=2) in several ways?  If so, take a few moments to highlight the language for your students.  Teach them the language of math.  Let them know that “is equivalent to”, “equals” and “is” are ways to say “=” and “times”, “multiplied by,” “multiplying” and “by” are different ways of saying the same thing.  After all, there is a lot more to math than just numbers!

            Written by: Tammy King


  1. I love this example of how you get teachers talking about the way they talk about math. I might have to steal this idea for my own trainings, if that's okay? You should check out this site with excellent video examples of using frames for teaching the language of math:

    1. Candis, feel free to use that mini-activity during your own trainings! If it is part of a slide presentation, please include the blog address ( as the original source of the activity. Let me know how it goes. Also - thanks for the link!

  2. Great wording to say the area of a circle formula, and good inspiration, awareness words and explanation of circle constant pi, in relation with PI DAY.

  3. Sweet. This is just what I needed. I am a GCU student taking an ELL class studying to be a Math teacher. I am also a GED teacher and I have opportunity to use these strategies often. Thanx.

    1. Anonymous,
      Glad you liked this post! Check back often for new posts, tips and tricks for teaching ELLs.
      Tammy King
      WIDA Blogger

  4. With proper credit given, is it okay to use this activity to help teachers understand how to unpack the academic language of math?

    1. Deb,
      Absolutely! The blog posts are here to help you. Also, check out the post on Tips on Creating Content Area Word Walls. I included links to some great math word walls. Also, I recently posted a list of various blog posts that can be incorporated into PD. Let us know how the activity went.