Use place value understanding to decompose to smaller units once using the standard subtraction algorithm, and apply the algorithm to solve word problems using tape diagrams

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.