This lesson is fairly straightforward. In math, “decomposing” refers to breaking a number into its parts. There are many ways to decompose any number. We practice this concept concretely, pictorially, and finally abstractly.
When students draw pictures of decomposing fractions, I advise them to always draw the whole first. This helps them work with mixed numbers more easily.
At this point, students can generally decompose fractions abstractly (using only numbers) with little to no help from me. We also introduce fraction number bonds now. There may be multiple ways to complete each number bond.