This ingenious counting book is all about feet. Not the kind with inches. The kind with toes, or paws, or claws. “1 is a snail. 2 is a person. 3 is a person and a snail.” The four-footed dog plus a snail equals five. The eight-footed spider plus a snail equals nine. Ten? Why, ten is a crab! And that means 20 is two crabs. Forty is four crabs, or ten dogs or...you get the picture. And so will kids. No doubt they’ll be eagerly creating their own pedimentary equations in no time. (Ages 4–8)