This genuinely clever math book uses rhyming couplets and riddles, as well as visual cues to help the reader find new ways to group numbers for quick counting. It’s a return to number sets, with none of those boring parentheses and <>signs. Here the rhyme gives a clue to the new ways of grouping numbers. For example: “Mama mia, pizza pie, / How many mushrooms do you spy? / Please don’t count them, it’s too slow, / This hot pie was made to go! / Let me give you some advice, / Just do half and count it twice.” A quick look at the pizza, and the reader can see each slice has the same number of mushrooms. Count by threes for half the pie, and double it. Each rhyme is given a double-page spread. The extra-large, brightly colored images leap off the page but never distract from the author’s intent. Some riddles are very challenging, but the author provides all the solutions in the back. Once the reader has seen the answers, the strategy is obvious and can be applied to other situations. Great fun for math enthusiasts and creative thinkers, this might also teach adults some new tricks. A winning addition. *(Nonfiction. 7-10)*