This Application Problem is a part of the Lesson 19, Unit 6, Grade 2.<br> In this lesson, students use square tiles to build an array made up of columns of 2 and relate it to even numbers on a number path up to 20. As multiples of two are circled on the number path, students observe that the ones digits are 0, 2, 4, 6, and 8. Now, students are ready to name all other whole numbers as odd.