Lesson 6

The purpose of this lesson is for students to organize, count, and represent a group of objects.

In the previous section, students organized and counted groups of ten and represented the base-ten structure of multiples of 10 using drawings, words, and numbers. In this lesson, students learn that a number can be grouped into tens and ones. As students group and count collections of objects, they consider how to organize the objects into groups of 10 and count the leftover objects that do not make a group of 10. Just as students reason that teen numbers are a ten and some ones, students use the collections to reason that you can have an amount of tens and some ones. At this time, students are not expected to write two-digit numbers, but some students may attempt to do so. Students read and write numbers in later lessons.

The same blackline master is used in both activities and again in centers, so teachers may want to make multiple copies for each student.

• Each group of 2 needs 1 bag of 52 single connecting cubes.

• Gather materials from previous centers: 
  • Check It Off, Stages 1–3
  • Five in a Row, Stages 1–4
  • Number Puzzles, Stages 1 and 2

How effective were your questions in supporting students’ thinking about units of ten today? What did students say or do that showed they were effective?