This Problem Set is a part of the Lesson 13, Unit 1, Grade 4. In this lesson, students extend their understanding of the standard algorithm for subtraction to multi-digit numbers requiring one decomposition. They begin pictorially using place value disks and a place value chart to model one decomposition to a smaller unit and work toward an abstract use of the algorithm, including in the context of a word problem. They use tape diagrams to model the part-whole relationship of the subtraction problem and to reflect on how the numbers are related.