Here is a FREEBIE that goes with my unit Out of this World! Odd and Even! It includes a worksheet with an explanation of the rules about adding odd and even numbers. This set also includes a odd/even color by number that makes a space ship!
Common Core Objectives:
2.OA.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.