This Problem Set is a part of the Lesson 2, Unit 4, Grade 1. In this lesson, students represent and decompose two-digit numbers as tens and ones and record their findings on a place-value chart, supported by Hide Zero cards. This is the first time they experience a representation of ten where 10 ones are not clearly visible. In the process, students share thoughts such as, "The 3 in 34 stands for 3 tens.