options: Ratios & Proportional Relationships: students learn to recognize, describe, represent, and reason with ratios, rates, proportional relationships, and percent.

Number Systems and Quantity: students learn to understand the complex number system and reason quantitatively.

Number & Operations in Base Ten: students learn to work with the base-ten system and build place value understanding.

Number & Operations - Fractions: students learn to understand fractions as numbers and may work with them using addition, subtraction, multiplication, and division.

Operations & Algebra: students learn to solve problems using algebraic thinking and operations such as addition, subtraction, multiplication, and division. They may learn to identify and explain arithmetic patterns, evaluate or manipulate numerical expressions, and reason with equations and inequalities.

Statistics & Probability: students learn to analyze and produce data distributions, and build understanding of univariate and bivariate data. They learn to interpret data, make statistical inferences, justify conclusions, understand rules of probability, and use probability to make decisions.

Measurement & Data: students learn to work with data and measure attributes such as time, money, length, area, and volume. They may learn to compare measurements to operations and convert between different units of measure.

Modeling: students learn to choose and use appropriate mathematics and statistics to analyze real-world empirical situations, improve decisions, and report on their conclusions and the reasoning behind them.

Geometry: students learn to classify geometric figures by their properties, and understand and compare the relationships between them. Students develop and use formulas to compute lengths, areas, and volumes, and they use transformations to generate new shapes and compare existing ones. Geometry can be studied with and without coordinates.

Counting & Cardinality: students learn to know number names and the count sequence, count to tell the number of objects, and compare numbers.

Functions: students learn to define, use, and evaluate functions to model relationships between quantities.
problem_activity: Narrative
The purpose of this activity is for students to describe patterns in the sequence of even and odd numbers when they count by 1. Students notice that even numbers are numbers that you count when you skip-count by 2 (MP7).
In order for all students to visualize the sequence, perform the activity where the whole class can be arranged in a circle with space for students to sit and stand. Depending on class size, the count may go beyond 20. It is ok for students to notice and wonder about even and odd numbers beyond 20, but maintain the focus throughout the lesson on numbers within 20.
Launch
Form the class into a circle with all students standing.
“We are going to count together by 1. The first person to count will say 0 and stay standing.”
“The next person will say their number and sit down. The next person will say their number and stay standing.”
“We will keep counting until everyone has said a number.”
As needed, demonstrate the stand-sit-stand-sit sequence.
Record the count:
[IMG]
Prompt students who are standing to say their numbers. (0, 2, 4, …)
Prompt students who are sitting to say their numbers. (1, 3, 5, …)
Activity
“Write down what you notice and what you wonder about the numbers in our count.”
3 minutes: independent work time
2 minutes: partner discussion
Monitor for students' responses that focus on even and odd number patterns to share in synthesis.
Student Facing
What did you notice? What do you wonder?
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
Share and record student responses.
Display:
[IMG]
“This is a list of all the even and odd numbers from 0 to 20.”
“What patterns do you notice?” (All the even numbers are numbers you say when you skip-count by 2. The digits 0, 2, 4, 6, 8 repeat in the ones place for even numbers. The digits 1, 3, 5, 7, 9 repeat in the ones place in odd numbers.)
“How could you use these patterns to tell if a number of objects is even or odd?” (If the number is an even number you say it when you skip-count by 2.)


correct_option_index: 4