Cluster 8: Developing Flexibility with Number

This cluster culminates the mathematical work of the grade as students build on their prior understanding of the relationship between numbers, addition and subtraction situations, strategies for addition and subtraction and properties of addition to develop flexibility with number. Students continue to use reasoning strategies to add and subtract within 20. By the end of this cluster students should be fluent with their facts within 10. Students who are fluent can solve for unknowns in addition and subtraction situations accurately, efficiently, and flexibly. To develop fluency, students should also be able to appropriately
choose strategies that best fit with solving a particular problem. (See About this Cluster and the Unpacking Document below for more details on this cluster.)