Properties, Equations, and Algebraic Thinking

Represent and understand addition as joining groups, combining sets, and increasing quantities using concrete materials, fingers, sounds, and balance models.

Understand and model subtraction as taking away, separating subsets, and finding the difference between two quantities.

Decompose numbers up to 10 into pairs in multiple ways using objects, visual diagrams, and equations.

Find the missing complement to make 10 for any number 1 to 9 using ten-frames, counters, and mental strategies.

Fluently add and subtract within 5 with automaticity and flexibility.

Develop strategic reasoning and recall addition facts within 10 and 20 using counting on, doubles, near doubles, and making ten.

Develop flexible subtraction strategies including counting back, think-addition, and subtracting through ten within 20.

Understand symbols (+, -, =), arithmetic properties (zero, commutativity, associativity), and find missing numbers in equations.

Solve a variety of contextual addition and subtraction word problems within 10, 20, and introductory contexts to 100 using multiple models.

Identify, describe, copy, extend, and create repeating and growing patterns using colors, shapes, sounds, movements, and numbers.