March 14, the mathematic high holiday known as Pi Day, is right around the corner. To celebrate everyone's favorite irrational number, we've rounded up some gifts to help the math aficionados in your life—the ones who know that pi is the ratio of the circumference of a circle to its diameter—observe Pi Day in proper fashion.

1. Simple As Pi Short-Sleeve Unisex T-Shirt; $25

The Mental Floss Store

Everyone needs a good arsenal of pi puns at their disposal, and this “Simple as 3.141592…” shirt is a classic. It comes in multiple colors, but the lilac and heather prism mint versions fit the retro vibe to a T.

Buy it: The Mental Floss Store

2. Pi Pie Pan; $25

Pi People/Amazon

If Pi Day passed and you didn't eat a pi pie, did Pi Day even happen? This specially shaped baking pan makes the equivalent volume of a 9-inch round pan, but obviously has more surface area than a standard pan. Pi puns and extra crust? Sounds like a win-win dessert.

Buy it: Amazon

3. Cutie Pi Unisex Onesie; $15

Threadrock/Amazon

Inspire a love of irrational numbers in the young mathematician-to-be in your life with this adorable cotton onesie, available in five colors for 6- to 24-month-olds.

Buy it: Amazon

4. Pi Hard Short-Sleeve T-Shirt; $25

The Mental Floss Store

To those who’ve felt like an action hero after memorizing pi to its hundredth digit, this shirt was made for you. It’s a loving tip of the cap to John McClane in all his torn-tank-top panache, complete with the words “Yippie-Pi-Day” at the top.

Buy it: The Mental Floss Store

5. Pi Shower Curtain; $32

Mental Floss Store

With this numerically charged shower curtain, you'll be able to memorize the first 4600 digits of pi while you wait for the water to warm up.

Buy it: Mental Floss Store

6. Mathematical Glasses; $38

UncommonGoods

You'll be toasting to a gift well done after they open this set of four pint glasses measuring out the number of ounces in Pythagoras's constant, the Golden Ratio, Euler's number, and of course, pi.

Buy it: UncommonGoods

7. Quantum Physics for Babies; $8

Sourcebooks Jabberwocky/Amazon

It's never too early to get your budding mathematician hooked on STEM! This quantum physics intro is meant for 1- to 3-year-old kids, but it's a good refresher for adults to brush up on their knowledge, too.

Buy it: Amazon

8. Pi vs. Pi Short-Sleeve T-Shirt; $25

The Mental Floss Store

If you still have a few dog-eared copies of Mad magazine in the basement, you’ll definitely appreciate this pi-themed take on the mag’s popular “Spy vs. Spy” comic.

Buy it: The Mental Floss Store

9. Spiral Pi Tattoo; $11

Anatomology/Amazon

This "classroom pack" of temporary tattoos means that when you and 44 of your closest pi pals practice memorizing pi's numerous digits, you never have to leave home without your cheat sheet.

Buy it: Amazon

10. Pi necklace; $25

Svaha

You can help the math geek in your life bring their love of numbers to their jewelry box with this stainless-steel pi necklace.

Buy it: Svaha

11. Insanity Math Leggings; $29

Insanity/Amazon

Spend your savasana meditating on the wonders of math in these equation-covered leggings.

Buy it: Amazon

12. Add & Subtract Abacus; $18

Melissa & Doug/Amazon

Ancient calculators make great toys when it comes to this colorful bead toy aimed at kids 2 and up. But once the young ones hit grade school, this specially marked abacus will help them visualize arithmetic while still seeing the equations listed out.

Buy it: Amazon

13. Hidden Figures; $14

William Morrow Paperbacks/Amazon

You saw the movie—now delve even deeper into the true stories of Katherine Johnson, Dorothy Vaughan, Mary Jackson, and the other African-American women who worked at NASA as "human computers" during the Space Race. Margot Lee Shetterly's best-seller reveals just how much ground-breaking work these brilliant mathematicians truly did, even while dealing with both gender discrimination and the Jim Crow era. And if you haven't seen the movie, stream it on HBO or purchase it here.

Buy it: Amazon