Lesson 2

The purpose of this lesson is for students to interpret different base-ten representations of multiples of 10.

Students make connections between different representations of multiples of 10. In the first activity, students work together to find the three representations (a number, ___ tens, and drawings of towers of 10) that show the same value and prove how they know the values are equivalent. In the second activity, students use what they have learned to match numbers to towers of 10. Throughout the lesson, when students explain how they know different representations match based on the their understanding of tens, the count sequence, or connections they make to the digits in the numerical representations, they look for and make use of structure and express regularity in repeated reasoning (MP7, MP8).

• Create a set of cards from the blackline master for the class. Each student will only need one card.
• Create a large chart titled “Representations of Tens” at the top. Draw three columns. Label columns “Number,” “Number of Tens,” and “Drawing.”

Reflect on how readily students work with the unit ten, rather than ten ones. Are students counting the connecting cubes in each tower to confirm there are ten? How can you provide opportunities for students to develop an understanding of the unit ten at their own pace?