Smart Abacus™ teaches children in Grades PreK-1 addition, subtraction, and how to write numerals. The app is revolutionary in its simplicity! This hand-on approach uses colorful, fun, step-by-step lessons and provides plenty of guided practice. Children learn basic addition and subtraction of single digit numbers and then advance to addition of two digit numbers and subtraction involving regrouping. Smart Abacus™ is available for most large phones, tablets, and computers. For even more mathematical learning and practice, use Smart Abacus™ with our award-winning PreK-Grade 1 Mathematical Reasoning™ books!