Tricky Teens are the numbers we most need to practice once students get their basic digits down. They are hard to recognize, comprehend, and even count. This set of activities gives primary students (Kindergarten and First graders, mainly) fun practice with Valentine Hearts as a theme. They will play a "Share the Love" helping game with the goal of identifying the numbers 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. They will see, say, write, and order these numbers in various and differentiated ways, with the overall goal of stronger number sense in mind.