This Application Problem is a part of the Lesson 24, Unit 4, Grade 2. Sammy bought 114 notecards. He used 70 of them. How many unused notecards did he have left? This Application Problem provides practice in taking from the hundred, as taught in Lesson 23. To encourage flexible thinking, you might invite some students to count up using the arrow way and invite others to solve by subtracting from the hundred.