Book excerpt: Counting sheep is supposed to help you sleep—but a room full of yaks, alpacas, and llamas would keep anyone awake in this counting book with a comical twist. Winner of the Mathical Book Prize! A glass of warm milk, reading, working on her knitting—nothing can help Clarissa get to sleep. When even counting sheep doesn't help her doze off, she tried pairs of alpacas instead. Two, four, six . . . then llamas by fives . . . then yaks by tens! But no one could sleep with a room full of bouncing, bleating, shedding animals. Determined to unravel her problem so she can get some sleep, Clarissa counts back down until she's all alone, and she can finally get some rest. Introducing addition and subtraction by ones, twos, fives, and tens, Sheep Won't Sleep is part bedtime story, part math practice— and the hilarious illustrations of spotted, striped, and plaid animals are sure to appeal to imaginative readers of all ages. A perfect-- and fun!-- way to introduce and reinforce counting in groups, this is sure to be a study- and bedtime favorite!