Lesson 1

The purpose of this lesson is for students to count groups of multiples of 10 objects in a way that makes sense to them.

In the previous unit, students learned that a ten is a unit made up of 10 ones. Students learned that teen numbers are made up of 1 ten and some more ones, using 10-frames, drawings, and expressions (\(10 + n\)). In kindergarten, students learned the counting sequence by ones and tens up to 100.

The purpose of this lesson is for teachers to formatively assess how students count objects up to 60 through two counting activities. In the first activity, students count objects and represent how many in a way that makes sense to them, then compare the ways they counted. In the second activity, students count bags of different quantities that are multiples of 10, and begin to make sense of grouping objects into tens. Suggested objects include pennies, paper clips, buttons, connecting cubes, inch tiles, counters, or any other objects around the classroom. Students should also be given access to cups, paper plates and double 10-frames to help them organize their collections if they would like.

A blackline master of the recording sheet is provided. Students use this sheet multiple times throughout the unit.  Consider making 10–12 copies per student.

• Each group of 2 students needs one bag of 40 objects.

• Each student will need the blackline master from the previous activity.
• Create 1 set of the following 6 bags of objects for each group of 12 students:
  • Bag A: 20 objects
  • Bag B: 40 objects
  • Bag C: 50 objects
  • Bag D: 60 objects
  • Bag E: 30 objects
  • Bag F: 10 objects

• Gather materials from previous centers:
  • How Close, Stages 1 and 2
  • Five in a Row, Stages 1-3
  • Number Puzzles, Stages 1 and 2

Identify who has been sharing their ideas in class lately. Make a note of students whose ideas have not been shared and look for an opportunity for them to share their thinking in tomorrow’s lesson.