MCC2.NBT.6; Add up to four two-digit numbers using strategies based on place value and properties of operations. This presentation includes student centered activities reviewing place value and using pace value to break apart and solve equations using up to 4 two digit numbers. Included are description and practice of both commutative and associative properties of addition, explanations for adding 2- 4 two digit numbers and quizzes to reinforce methods, using models to write and solve equations and quizzes to practice both equations and word problems. All activities provide opportunities for students to participate. My students solve equations on their desks in dry erase markers.