Personalized Panda Proof That Math Teachers Multiply Funny T-Shirt. funny math themed baby quote with panda says I'm proof that math teachers multiply Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.