This Application Problem is a part of the Lesson 9, Unit 6, Grade 1. Emi and Julio together have 17 pet mice. How many mice might each child have? Extension: Who has more, and how many more does that child have? Today's Application Problem practices decomposing a two-digit number and can have more than one correct answer. This work supports students' compositions and decompositions when they begin Topic C in Lesson 10.