The Cat in the Hat spends the 100th Day of School visiting Sally and Dick's classroom to show how some simple tools—including a hundreds chart, ten frame, number line, and 100 silly hats—make it easy and fun to count, add, subtract, multiply, and divide. While this is a natural choice for celebrating the 100th Day of School, The 100 Hats of the Cat in the Hat is perfect for anyone, anytime, who wants to nurture a beginning reader's interest in numbers! Fans of the hit PBS show The Cat in the Hat Knows a Lot About That! will be delighted at this new addition to the Learning Library series.