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

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

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.

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

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.

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.

Functions: students learn to define, use, and evaluate functions to model relationships between quantities.

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

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.

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.
problem_activity: Narrative
The purpose of this activity is for students to find the area of rectangles by counting squares. Larger rectangles provide more opportunities for students to practice counting strategies using the structure of the rectangles to group the individual squares (MP7). Rectangles in this activity lend themselves to show groups of twos, fives, or tens in rows or columns. Students may also see other ways to create equal groups within rectangles. For example, the second rectangle with an area of 30 square units can be seen as 3 groups of ten. If students finish quickly, encourage them to confirm the area by counting another way. Emphasize that each area is in square units.
MLR8 Discussion Supports.
Synthesis: For each observation that is shared, invite students to turn to a partner and restate what they heard, using precise mathematical language, such as area or square units.
Advances: Listening, Speaking
Launch
Groups of 2
Activity
“Find the area of each rectangle. Be ready to explain your reasoning.”
5–7 minutes: independent work time
Monitor for counting strategies such as:
Counting the squares in a row or a column and then skip-counting by that number for subsequent rows or columns.
Grouping by twos, fives, tens, or other numbers.
“Now share your strategies with your partner.”
2–3 minutes: partner discussion
Student Facing
Find the area of each rectangle and include the units. Explain or show your reasoning.
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Student Response
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Advancing Student Thinking
If students miscount the square units in the rectangles, consider asking:
“Tell me how you counted the squares.”
“How could you keep track of your count as you count the squares?”
Activity Synthesis
Invite 3–4 previously selected students to share how they found the area of one of the rectangles. Try to highlight a variety of strategies.
Consider asking, “Did your strategy change from rectangle to rectangle?”


correct_option_index: 5