options: 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.

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.

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

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.

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.

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.

Number & Operations - Fractions: students learn to understand fractions as numbers and may work with them using addition, subtraction, multiplication, and division.
problem_activity: Narrative
The purpose of this activity is for students to use their understanding of place value to determine the number described in a riddle. Students then write the number of hundreds, tens, and ones, and represent the value as a three-digit number.
MLR8 Discussion Supports.
Display sentence frames to support partner discussion about each number written on the table: “I agree because . . .” or “I disagree because . . . .”
Advances: Conversing
Engagement: Provide Access by Recruiting Interest.
Provide choice. Invite students to decide the order in which they complete the work. They can start with any of the riddles, as long as they complete all of them.
Supports accessibility for: Attention, Social-Emotional Functioning
Required Materials
Materials to Gather
Base-ten blocks
Launch
Groups of 2
Give students access to base-ten blocks.
“I have 4 hundreds, 3 ones, and 2 tens.”
“Which of these shows the total value written as a three-digit number? Explain how you know.”
Display 432, 234, 423.
30 seconds: quiet think time
1 minute: partner discussion
Share responses.
Activity
“You are going to solve number riddles using base-ten blocks.”
As needed, demonstrate the task with a student.
“Take turns reading the clues, while your partner uses blocks to make the number.”
“Make sure you agree before adding each number to the table.”
10 minutes: partner work time
If students finish early, ask them to write their own riddles and trade them with other groups to solve.
Monitor for students who recognize they need a zero when writing the three-digit number in places where there were no tens or no ones.
Student Facing
Solve each riddle and write the three-digit number. Use the table to help you organize the digits.
| riddle | hundreds | tens | ones | three-digit number |
|--------|----------|------|------|--------------------|
|   1    |          |      |      |                    |
|   2    |          |      |      |                    |
|   3    |          |      |      |                    |
|   4    |          |      |      |                    |
|   5    |          |      |      |                    |
|   6    |          |      |      |                    |
I have 2 ones, 7 tens, and 6 hundreds.
I have 3 ones, 5 tens, and 2 hundreds.
I have 7 hundreds, 5 ones, and 3 tens.
I have 5 hundreds, no tens, and 9 ones.
I have 4 ones, 6 tens, and 3 hundreds.
I have 8 tens, 1 hundred, and no ones.
Student Response
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Activity Synthesis
Invite previously selected students to share what they noticed when writing 509 and 180.
As needed, write 81, 801, and 810 and ask, “What is the difference between 81, 801, and 810?”


correct_option_index: 5