Pine cones. Stock-market quotations. Sunflowers. Classical architecture. Reproduction of bees. Roman poetry. What do they have in common? In one way or another, these and many more creations of nature ...

1, 11, 21, 1211, 111221. These are the first five elements of a number sequence. Can you figure out what comes next? If you're trying a bunch of arithmetic operations to make the numbers work, you're ...

Practice time! Build, read, & write three-digit numbers using base-10 blocks and symbols. Practice time! Build, read, write (in standard and expanded form), and represent three-digit numbers using ...

Fourteen years ago, the mathematicians Dusa McDuff and Felix Schlenk stumbled upon a hidden geometric garden that is only now beginning to flower. The pair were interested in a certain kind of oblong ...