This Fluency Activity is a part of the Lesson 2, Unit 3, Grade 1. This fluency activity strengthens the understanding of place value and prepares students for Module 4. If students already have Hide Zero cards from previous work, only the final page needs to be copied and distributed. Show students a number from 10 to 40 with Hide Zero cards. Students say an addition sentence with 10 as an addend. As students say the sentence, break apart the Hide Zero cards to model the equation.