Lesson 17

The purpose of this lesson is for students to compare and order numbers based on the value of the tens and ones digits.

In this lesson, students compare and order numbers up to 99. Ordering numbers requires students to apply what they have learned about comparing two numbers, and allows them to see that a number can be greater than one number, while less than another. As students reason about how to place numbers and explain how they order numbers, they deepen their understanding of the structure of whole numbers and the base-ten system (MP7). In the first activity, students begin comparing and ordering familiar representations such as base-ten diagrams, words (_____ tens and _____ ones), and expressions that show the value of tens and ones. These representations allow students to use the value of the digit in the tens and ones places to help them put the quantities in order. In the second activity, students compare numbers less than 99 to the benchmark numbers 5, 10, 50, and 99.

• Create a set of cards from the blackline master for each group of 2. 

If you were to teach this lesson over again, what activity would you redo? How would your proposed changes support student learning?