Standards for Mathematical Content in the CCSSM  

In the domain of Operations and Algebraic Thinking (K–Grade 5) students learn what kinds  of problems addition and subtraction solve and increasingly sophisticated ways of thinking  and reasoning about addition and subtraction with small numbers. In the domain of Number  and Operations in Base Ten (K–Grade 5), students learn to compose and decompose  numbers according to place value and to make sense of methods for adding and subtracting multidigit numbers. In the domain of Number and Operations—Fractions (Grades  3–5), students extend their understanding of addition and subtraction to fractions. 

Standards for Mathematical Practice in the CCSSM  

Opportunities to engage in all eight of the Standards for Mathematical Practice described  in the Common Core State Standards occur throughout the study of addition and subtraction, but the following standards may be especially appropriate for emphasis:  

• 3 Construct viable arguments and critique the reasoning of others. Students  engage in this practice when they make sense of methods of addition and subtraction and when they explain their methods with the aid of math drawings.  

• 4 Model with mathematics. Students engage in this practice when they use addition or subtraction to solve problems and when they examine situations critically to  determine whether addition or subtraction apply.  

• 7 Look for and make use of structure. Students engage in this practice when  they apply properties of addition or decompose and recompose numbers in order  to add or subtract. For example, to add 8 + 7 a student might break 7 into 2 + 5,  combine the 2 with 8 to make a 10, and then add on the remaining 5 to make 15.