If you love math, you may just love solving this formula to figure out the hidden message. This pi formula from Doodlecraft is easy to iron onto a basic shirt with heat transfer vinyl. This conversation-starter will leave people puzzled all day with a not-so-obvious message about your so-obvious love of pi.

A little bit of belt and a whole bunch of numbers can go a long way with this DIY pi belt from Pieces by Polly. Start with either a ready-made belt or some fabric and interfacing to make belt material. Then, using transfer paper and an iron, transfer the numeric value of pi onto the belt. Wearable and made to perfection!

If you want a subtle but educational pi fashion statement, try this pi-bracelet activity from Pink Stripey Socks. Assign colored beads to different numbers and have the kids string them onto cord according to which number comes next in pi's numeric value. Or, use black and white beads to distinguish between odd and even number in the pi sequence. The kids will enjoy learning and later sporting their festive bracelets.

Easier than painting or sewing on a pi symbol, you can use an iron-on symbol like this one from Welcome to the Mouse House. Download and print the symbol, cut a fabric symbol to match, and iron Heat and Bond onto the wrong side of the symbol before ironing onto the shirt. Simple but effortless!