In a previous unit, students practiced adding and subtracting within 10, with an emphasis on adding or subtracting 1 and 2. They also considered the commutative property in the context of story problems. Students classify sums as “got it” or “not yet” depending on whether they know the sum quickly or not. There is no specific time expectation for students to classify sums as “got it,” but class discussion allows students to consider what it means to “get” the sum. Students discuss ways of finding sums within 10 that they don’t know yet.

As students find sums, they may count on, know some sums from memory, apply the commutative property, and use related sums. Students work towards the end-of-year fluency goal for grade 1 which requires demonstrating fluency for adding and subtracting within 10. "Fluency" is defined as being efficient, flexible, and accurate.

Expression cards are cut out by students during this lesson, but can be prepared ahead of time if preferred. The cards students make will be used throughout the unit in lesson and center activities.

"Fluency" is defined as being efficient, flexible, and accurate. How is this definition different from your previous understanding of fluency? How will it change the way you assess student fluency of addition and subtraction within 10?