Are you looking for an activity for Valentine’s Day? Then check out this list of assorted Valentine related math lessons!

Let's start the list with some brain teasers, lessons, and activities from NCTM. I included the grade level when given and ordered them roughly from elementary to high school level.

How Big Is Your Heart?

Grade: Pre-K – 2

Topic: measurement, length, width, circumference, comparing sizes

http://illuminations.nctm.org/Lesson.aspx?id=767

The Beat of Your Heart

Grade: 3 – 5

Topic: Collecting, organizing, and interpreting data, making predictions based on data

http://illuminations.nctm.org/unit.aspx?id=6545

Heart Construction

Topic: build a shape out of other shapes

http://illuminations.nctm.org/BrainTeasers.aspx?id=4915

Heartifacts

Grade: 6 – 8

Topic: interpreting factual information to solve related problems

https://illuminations.nctm.org/Lesson.aspx?id=778

Heart Plot

Topic: coordinates, expressions containing variables

http://illuminations.nctm.org/BrainTeasers.aspx?id=4910

Heart Shaped Words

Topic: types of numbers (even/odd, positive/negative, prime, square, integer), arithmetic sequence, normal distribution, area, right triangle, exponents

http://illuminations.nctm.org/BrainTeasers.aspx?id=4901

Heart Graph

Topic: find equations to graph a heart

http://illuminations.nctm.org/BrainTeasers.aspx?id=4908

Love Unlimited

Grade: Algebra 2, precalculus, calculus

Topic: Domain and range, graph transformations, reflections and rotations, maximum and minimum values, area of a region

http://www.nctm.org/Publications/Mathematics-Teacher/2016/Vol109/Issue6/Love-Unlimited/

If none of those NCTM activities make your heart go pitter-patter, how about this exploration of the geometry of a Papa John’s heart-shaped pizza?

https://emergentmath.com/2011/02/14/how-do-you-slice-this-papa-johns-heart-shaped-pizza/

Or maybe this lesson that looks at modeling Romeo and Juliet’s feelings for each other through recursively-defined functions. (not a free lesson)

http://mathalicious.com/lessons/romeo-juliet

Alternatively, any of these nine activities for Valentine’s Day (and one for President’s Day) from Newton, MA-based Yummy Math.

http://www.yummymath.com/2016/valentines-and-presidents-days/

Maybe you are only looking for a Valentiny warm-up activity? How about a week worth of estimation practice?

http://www.estimation180.com/blog/valentines-day-estimates

If you want to take the holiday as an opportunity to explore the intersection of math and art, Math Munch is always a great source for fascinating mathematical finds. This Valentine’s Day themed post contains mathy Valentine cards (featuring Sierpinski triangles and cardioids) and Mobius strip hearts.

https://mathmunch.org/2013/02/11/the-sierpinski-valentine-cardioids-and-mobius-hearts/

To see the Mobius strip hearts in action in a classroom, check out the following link.

http://mathequalslove.blogspot.com/2013/02/valentines-day.html

What about making Valentine card art by translating, rotating, and scaling hearts in this lesson from ScienceFriday.com? (While you are at it check out their excellent list of Valentine’s Day science articles.)

http://www.sciencefriday.com/educational-resources/make-a-mathy-valentine/

This excellent GeoGebra applet was inspired by the ScienceFriday lesson. https://www.geogebra.org/m/varztYRq

Lastly, you could explore all the ways that WolframAlpha computes Valentine’s Day with your class.

http://blog.wolframalpha.com/2010/02/12/computing-valentines-day-with-wolframalpha/

When you are done planning your Valentine’s Day math class, make sure to take the time to send someone you love a Valentines Math-O-Gram. Nothing says I love you quite like animated polar graphs.