This Fluency Activity is a part of the Lesson 13, Unit 1, Grade 1. This activity addresses the core fluency objective for Grade 1 of adding and subtracting within 10. Give Partner A a set of single-sided 5-group cards and Partner B a set of single-sided numeral cards. Tell students to sit facing each other and line up their cards in front of them, face down. Instruct students to take turns flipping over one of their cards and one of their partner's cards to try to make a ten.