Lesson 1

The purpose of this lesson is for students to count to answer “how many” questions about groups of up to 20 objects.

In previous units, students answered “how many” questions about up to 10 objects. With smaller groups of objects, students could sometimes figure out how many there were without counting. Students developed methods such as moving and counting objects, lining up objects, or placing and moving objects on a counting mat. This exploratory lesson provides formative data for teachers on how students apply counting concepts from previous units to larger groups of objects. Students will be introduced to the written numbers 11–20 over the course of the section and will have opportunities to practice tracing and writing the numbers. In this lesson, display written numbers whenever students share their count.

Students can be invited to bring objects from home to use in counting collections throughout this unit and in centers. The objects in the collections should be small enough to fit on a counting mat, such as buttons, counting bears, coins, connecting cubes, or two-color counters. 

• Each student needs a collection of 11–20 objects.

• Create a pile of 4 connecting cubes to display.
• Create a pile of 13 connecting cubes to display.
• Students need the collections of 11-20 objects from the previous activity.

• Gather materials from:
  • Subtraction Towers, Stage 1
  • 5-frames, Stages 1 and 2

How have 5- and 10-frames supported students in keeping track of and accurately counting groups of objects?