Book excerpt: Children in prekindergarten focus on counting and gradually master the essential one-to-one matching of an object to a number. By the end of second grade, they can represent one, two and three digit numbers, understand simple fractions and apply a variety of facts and strategies to add and subtract skilfully. This book supports this progression by inviting students to count and order ducklings in a line, compute the total cost of several items on a menu and play a variety of games that reinforce their understanding of number, addition and subtraction.