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 counting methods, such as moving 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 counts.

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.