If you're the type to understand the world through math, these elegant Equations That Changed the World zipper bags are for you. Available in three styles, the cylinder makes a great pencil case or compact toiletry bag, the roomy rectangular bag will hold your medium to larger items – use it as a makeup bag or dopp kit, and the telescoping bag extends to house your brush pens and a full-size pair of scissors – and when open and retracted, it transforms into a desktop pencil cup with all your tools on display.
