Contemos con cuidado
In previous lessons, students counted groups of up to 20 objects and kept track of the objects that have been counted. In this lesson, students count the same collection as a partner, both to compare different ways of organizing and keeping track of collections of objects and to notice that the total number of objects stays the same. As students use and observe a variety of ways to count collections, they begin to understand that the order or arrangement that objects are counted in does not affect the number of objects. Students will further explore the conservation of number when a group of objects is rearranged in a future lesson.
- Answer “how many” questions about groups of up to 20 objects.
- Know that counting a group of objects will yield the same number, regardless of their arrangement or how they are counted.
- Veamos si obtenemos el mismo número que nuestra pareja cuando contamos el mismo grupo de objetos.
Materials to Gather
- Collections of objects
- Connecting cubes
- Counting mats
- Materials from previous centers
- Number cards 0–10
Materials to Copy
- Find the Pair Stage 1 Recording Sheet, Spanish
- Create a pile of 18 connecting cubes to display.
- Each student needs a collection of 11–20 objects.
- Create a pile of 16 connecting cubes to display.
- Before playing, remove the cards that show numbers greater than 5.
- Number Race, Stages 1 and 2
- Subtraction Towers, Stage 1
- 5-frames, Stages 1 and 2
|Activity 1||10 min|
|Activity 2||10 min|
|Activity 3||25 min|
|Lesson Synthesis||5 min|