Funtastic Frogs Addition and Subtraction - Funtastic Frogs Activity Books Author:Jill Osofsky This book is one in a series of books designed to develop children's mathematical thinking. Each book supports the use of Funtastic Frog Counters in activities that teach key mathematical concepts. In Funtastic Frogs: Addition and Subtraction, Grades K-2, children use the frog counters to: count on to add; combine groups to add; write addition s... more »entences; take away to subtract; write subtraction sentences; understand the meaning of addition and subtraction; learn the vocabulary for addition and subtraction.« less