# Operations and Algebraic Thinking

## Contact(s)

Judith Spitzli
515-402-8600

Iowa Core Mathematics Documents

Iowa Core Mathematics Support - Resources to support Iowa Core Mathematics.

## Standards in this domain:

### Represent and solve problems involving addition and subtraction.

• 2.OA.A.1 Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.1

### Add and subtract within 20.

• 2.OA.B.2 Fluently add and subtract within 20 using mental strategies.2 By end of Grade 2, know from memory all sums of two one-digit numbers.

### Work with equal groups of objects to gain foundations for multiplication.

• 2.OA.C.3 Determine whether a group of objects (up to 20) has an odd or even number of members, e.g., by pairing objects or counting them by 2s; write an equation to express an even number as a sum of two equal addends.
• 2.OA.C.4 Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends.

Printed from the Iowa Department of Education website on April 16, 2014 at 8:16pm.