This Fluency Activity is a part of the Lesson 38, Unit 1, Grade 1. This activity addresses the fluency objective for Grade 1 of adding and subtracting within 10. Students place the deck of cards face down between them. Each partner flips over two cards and subtracts the smaller number from the larger number. The partner with the smallest difference keeps the cards played by both players that round. The player with the most cards at the end of the game wins.