Subtraction for second grade. Students determine the missing number using Common Core Math Strategies; given the minuend and difference, students use various strategies to determine the subtrahend, example 15 - ? = 6 15 - 9 = 6. There are 26 cards with 8 to a page and the numbers used go up to 20. A number line, recording sheet, answer key, and Exit Tickets are included. Extend and Enrich Learning Subtraction, this activity is perfect for students who finish early. · Extend the activity let the