Mott Media has republished the version of Ray's Arithmetic from the late 1870's and early 1880's. This book introduces the four operations of addition, subtraction, multiplication, and division, along with counting and other basic skills. It can be used to guide your teaching for about two years - through grades 1 and 2. It goes farther than the average second grade course, but with Ray's mental system many second graders are able to do this work.