This Fluency Activity is a part of the Lesson 38, Unit 1, Grade 1. This activity continues to maintain students' understanding and use of teen numbers as 10 and some more. Hide Zero cards are made so that the single digit cards can be laid on top of the 10 card to create teen numbers. The digit in the ones place can be lifted to show the zero from the 10 hiding behind the single digit card. Use the Hide Zero cards to show teen numbers.