Understanding Addition & Subtraction is one in a series of Math Perspectives Understanding Numbers stations.
The goal of the 8 stations in this set is the development of computational fluency with multi-digit numbers. The tasks focus the students on using the underlying structure of number to combine, break apart and compare numbers.
Students learn to combine quantities by reorganizing them into the largest groups possible and to subtract by breaking numbers apart and recombining what's left. They also learn to find the difference between numbers using a variety of strategies.
Models are used to help learners understand what is happening to the numbers and leads them to the place where they can do the operations without models.
Each task requires them to explain their strategies using words, drawings and/or symbols.