2.OA.C. Work with equal groups of objects to gain foundations for multiplication.

• Delayed Gratification

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.

• Buttons odd and even
• Red and Blue Tiles

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.

• Counting Dots in Arrays
• Partitioning a Rectangle into Unit Squares