Checked and updated annually, ideas and resources for Valentine’s Day …
(Whilst some of these resources were created some time ago, they are still ideal for Valentine’s Day.)

From Desmos, send one of their great math-o-grams to your mathematical friends!

For an alternative source of Valentine’s cards, we can turn to NASA!

Alternatively, try this post, or an earlier post.

From Sarah Hart, on M+a+t+h=Love, we have a whole collection of Valentine’s Day activities.
(Note that you will find further details on the Mobius strip activity below.)

From OCR, we could try this puzzle.

Here’s a Valentine logic starter from Transum.

The excellent Maths Careers site is managed and maintained by the Institute of Mathematics and its Applications. If your students wonder where Mathematics is used, they will find plenty of answers here. See, for example, Who employs mathematicians?  

For Valentine’s day we have an appropriate article from Maths Careers, did you know that 6 is a kissing number?! And for your Further Mathematicians, What is the equation for a heart?

Also, from Maths Careers, see this post with instructions on how to make this wonderful pair of linked Möbius hearts.

If you wish to get creative and try this, I advise watching the Numberphile video carefully (embedded further down this page), following the instructions worked, as you can see from my creation here! I can verify that unless you follow the instruction to make sure the twist in each strip is in a different direction you will end up with a mess! Quite an interesting mess, but certainly not two hearts!….

Note the Desmos graphs on my strips. I created a file in Word valentine-mobius-hearts (or pdf: valentine-mobius-hearts) with Desmos images in a table. Adding dotted borders to the table gives guidelines for cutting. I began each cut by using the end of a paperclip to pierce the paper.

I printed the document to create my strips and then printed again on the reverse. I then cut out and trimmed the strips so there was no white space at the end – the picture here has been made using strips 10 cells long.

From Numberphile, Professor Ron Graham discusses the Happy Ending Problem and from Dr Emily Riehl, The Stable Marriage Problem. We also have a great Parametric Heart spreadsheet from Think Maths.

This Valentine Relay from Chris Smith is excellent as are all the other relays in this excellent set of resources. You can find more excellent resources from Chris on TES and follow him on Twitter here.

From Maths4Everyone, try this Valentine’s Day Maths Treasure Hunt. Students have to work out the costs of gifts, meals and other outings for Valentine’s Day.

You can find a whole collection of Treasure Hunts from Maths4Everyone here.

From Clarissa Grandi on Artful Maths, a selection of creative Valentine’s Day maths activities, including an origami neat little paper heart, drawing cardioids and plotting parametric hearts, and a slotted paper heart globe 

From Plus Magazine, see their review of Strange Attractors: Poems of love and mathematics which includes the poem, “Where the Kissing Never Stops” by Ann Calandro which the reviewer points out very effectively use mathematical imagery, for tangential curves (“kissing curves”).

A song which has always made me smile from The Klein 4…

Remaining with the loving theme you can express your feelings for WolframAlpha!

and from the WolframAlpha archives, Computing Valentine’s Day.
Sending Valentine’s good wishes to mathematicians everywhere!……………..