For students in grades 2nd through 5th who are not using a variety of strategies for addition, this doubles vs. near doubles (also called doubles + 1) sort will give them extra practice with these helpful strategies and will help them makes gains on their addition timed test. This activity can be copied on card stock and used as a fluency center, partner activity or used individually in the regular classroom, intervention and special education. All addition fact cards are sums within 20 as mandated secure at the end of second grade by the Common Core Standards. Use the cards provided or a set of flashcards you have on hand. Color sorting mats, as well as black line masters are included. Happy sorting!