**Lesson objective:** Count any number of objects (within 20) and represent the objects with a written numeral.

This lesson helps to build fluency with writing numbers from 0 to 20 and representing a number of objects with a written numeral. Number racks are used here because keeping track (differentiating counted from uncounted entities) is more easily done by moving objects into a counted set. This work develops students' understanding of cardinality - that the number that ends the counting sequence represents how many objects are in the group.

Students engage in Mathematical Practice 6 (Attend to precision) as they express how they know that their count is accurate. Students communicate precisely with others and try to use clear mathematical language when discussing their reasoning. Students are provided opportunities to justify why their answer represents a quantity just counted by answering questions such as "How do you know?" and "How did you figure that out?"

**Key vocabulary:**

**Special materials needed:**

- Counting objects (blocks, cubes, counters, pennies, etc.)
- Paper or an individual white board for recording numerals