Help your students use addition and subtraction within 20 to solve word problems with unknowns in all positions. Students will practice three types of problems: result unknown, change unknown, and start unknown. There are 2 sets of differentiated cards included in this download. One set includes the number sentence and the other does not. Both sets come in color and black and white. Task cards are a wonderful tool to have on hand for independent practice, a game of SCOOT, Kagan activities,