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

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

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.

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.

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.

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

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.

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

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.

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.
problem_activity: Narrative
The purpose of this activity is for students to practice adding within 1,000 with an emphasis on adding by place. Throughout the activity, students have opportunities to explain their methods and representations to peers. In the synthesis, students have opportunities to question and critique the work of their peers as they compare different methods for adding three-digit numbers and different representations that show composing units when adding by place (MP3).
This activity uses
MLR8 Discussion Supports
. Advances: conversing
Engagement: Provide Access by Recruiting Interest.
Provide choice. Invite students to decide which problem to start with and the strategy they feel most comfortable solving with.
Supports accessibility for: Social-Emotional Functioning, Organization, Attention
Required Materials
Materials to Gather
Base-ten blocks
Launch
Groups of 2
Give students access to base-ten blocks.
Activity
“We are going to practice adding 2 three-digit numbers. You can find the value of each sum in any way that makes sense to you. After some time working independently, you can continue working with a partner.”
MLR8 Discussion Supports
Display sentence frames to support students when they explain their strategy:
“First, I _____ because . . .”
“I noticed _____ so I . . .”
5 minutes: independent work time
4 minutes: partner work time
“Choose one expression and share how you found the value of the sum with a new partner.”
3 minutes: partner discussion
Monitor for students who use base-ten blocks, base-ten diagrams, or other representations that clearly show adding by place.
Student Facing
Find the value of each expression. Show your thinking.
\(384 + 409\)
\(757 + 152\)
\(262 + 438\)
\(575 + 166\)
Student Response
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Advancing Student Thinking
If students lose track of the tens or hundreds they compose (for example,
\(384 + 409 = 783\)
) or do not compose a ten or hundred, prompt students to explain their thinking and any representations they use. Consider asking:
“How does your representation show that you composed a new unit?”
“What could you add to your representation to help you keep track of any tens or hundreds you compose?”
“How could you use base-ten blocks to show your thinking?”
Activity Synthesis
Invite 2–3 previously identified students to share their representations and how they found the value of the sums.
“How are these methods the same? How are they different?”


correct_option_index: 7