Lesson 8
Varias representaciones de decenas y unidades
Lesson Purpose
The purpose of this lesson is for students to interpret base-ten representations of two-digit numbers.
Lesson Narrative
In previous lessons, students learned that the digit on the left of a two-digit number tells the number of tens and the digit on the right tells the number of ones.
In this lesson, students interpret three different base-ten representations: base-ten diagrams, _____ tens _____ ones, and addition expressions that represent the value of each digit. This is the first time students see expressions representing two-digit numbers other than 10 + n expressions representing teen numbers. Students match representations that show the same value.
At this time, students are not expected to write two-digit numbers, but continue to make sense of how to read and say them based on their base-ten structure. The teacher should record two-digit numbers when students say them.
- Engagement
- MLR7
Activity 1: Comparemos representaciones de una colección
Learning Goals
Teacher Facing
- Interpret different base-ten representations of two-digit numbers (drawings, words, and addition expressions).
Student Facing
- Pensemos cómo se pueden mostrar los números de dos dígitos.
Required Materials
Materials to Gather
Materials to Copy
- Representations of Tens and Ones, Spanish
- Grab and Count Stage 2 Recording Sheet, Spanish
Required Preparation
Activity 2:
- Create a set of cards from the blackline master for each group of 2–4.
CCSS Standards
Addressing
Lesson Timeline
| Warm-up | 10 min |
| Activity 1 | 10 min |
| Activity 2 | 15 min |
| Activity 3 | 15 min |
| Lesson Synthesis | 10 min |
| Cool-down | 0 min |
Teacher Reflection Questions
What was the best question you asked students today? Why would you consider it the best one based on what students said or did?