CalcuLadder® 1 includes drill Levels 1 through 16, which cover basic addition and subtraction. Your student is thoroughly drilled on all addition and sub­traction facts with answers less than or equal to 20. Drills 1-14 have a suggested time goal of 2 minutes. The drill Levels are carefully sequenced to add new facts while reviewing previous ones. The final two Levels provide a comprehensive review of all facts, and have a suggested time time goal of 3 minutes. The purpose is to get basic addition and sub­traction facts down cold, so that the student knows the answers instantly. Use CalcuLadder 1 in Grades 1, 2, 3, or higher for a really solid foundation or to fill gaps in basic math mastery!