Lesson 19
Story Problems and Equations
Warmup: Choral Count: 0100 and Back Again (10 minutes)
Narrative
The purpose of this Choral Count is to invite students to practice counting by 10 and notice patterns in the count. These understandings help students develop fluency with the count sequence and will be helpful as students begin working with numbers beyond 10.
Launch
 "Count by 10, starting at 0."
 Record as students count.
 Stop counting and recording at 100.
 "Count backward by 10, starting at 100."
 Record as students count.
 Stop counting and recording at 0.
Activity
 "What patterns do you see?"
 1–2 minutes: quiet think time
 Record responses.
Student Response
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Activity Synthesis
 "How did you know what number would come next as you counted backward?"
Activity 1: Lotería (20 minutes)
Narrative
The purpose of this activity is for students to write two equations to match each story problem. Students solve the problems in any way that makes sense to them. They may write an equation in which the total is before the equal sign, or that uses the add in any order property. Students may write equations with a box around the answer, an empty box for the unknown, or a combination of both.
The story problems in this activity are about the Mexican game, Lotería. During the launch, students learn how the game is played and some similarities between Lotería and Bingo. Before sharing information about the game, ask students if anyone has heard of this game, and what they know about how it is played. Consider showing students pictures of Lotería boards and cards.
Advances: Reading, Representing
Supports accessibility for: Organization, Attention
Required Materials
Materials to Gather
Launch
 Groups of 2
 Give students access to connecting cubes or twocolor counters.
 “We have been solving problems about different games people play. Today we will solve problems about a game called Lotería. Has anyone played Lotería?"
 Share responses.
 If needed, "Lotería is a very popular game played in Mexico. It is similar to the game bingo. Instead of numbers, the caller picks a card with a picture on it. If the picture is on your board, you cover it. Many people use beans or small rocks to cover the pictures. When you have four pictures covered in a row you call out, ‘Lotería!’”
 Consider displaying images of the game boards and picture cards used in the game.
Activity
 “Let’s solve some problems about students playing Lotería.”
 Read the task statement.
 6 minutes: independent work time
 “Share your equations with your partner. Explain how they match the stories.”
 3 minutes: partner discussion
Student Facing

10 picture cards have been called.
7 of the pictures are on Mai’s board.
How many of the pictures are not on Mai’s board?
Show your thinking using drawings, numbers, or words.Equation: ________________________________
Equation: ________________________________

Lin has 10 beans to play with.
3 of her beans fall on the floor.
How many beans does Lin have to play with now?
Show your thinking using drawings, numbers, or words.Equation: ________________________________
Equation: ________________________________

10 students are playing Lotería.
Some students are using beans on their boards.
Some students are using small rocks.
What are some ways to show how many students are using beans and how many are using small rocks?
Show your thinking using drawings, numbers, or words.Equation: ________________________________
Equation: ________________________________

Noah has 3 pictures covered on his board.
His brother has 10 pictures covered.
How many fewer pictures does Noah have covered than his brother?
Show your thinking using drawings, numbers, or words.Equation: ________________________________
Equation: ________________________________
Student Response
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Activity Synthesis
 Invite students to share the equations they wrote for each story problem and explain how they match the story.
Activity 2: What's Your Question? (15 minutes)
Narrative
The purpose of this activity is for students to make sense of story problems that do not include a question. In some story types, like Add To, Change Unknown, students can infer what the question in the story is without it being asked. In problem types like Compare, there are multiple questions that can be answered, all of which have different equations, solutions, and methods of solving. In presenting students with problems without questions, they strengthen their understanding of connections between story problems and the equations that match. When students formulate their own questions they need to make sense of the given information in order to understand what is given and what is unknown (MP1).
Required Materials
Materials to Gather
Launch
 Groups of 2
 Give students access to connecting cubes or twocolor counters.
Activity
 "Now you will read story problems that don't have a question. Your job is to write a question for each problem. Then solve the problem."
 5 minutes: independent work time
 “Share your question and equation with your partner.”
 3 minutes: partner discussion
 Monitor for students who wrote different questions for the problem with Diego and Noah.
Student Facing

Clare has 3 pictures covered on her board.
She covers some more.
Now she has 9 pictures covered.What is a question you can ask about the story?
Show your thinking using drawings, numbers, or words.
Which equation matches how you solved the story problem?
\(3 + \boxed{\phantom{6}} = 9\)
\(9  3 = \boxed{\phantom{6}}\)

Diego has 2 beans on his board.
Noah has 9 beans on his board.What is a question you can ask about the story?
Show your thinking using drawings, numbers, or words.
Which equation matches how you solved the story problem?
\(2 + \boxed{\phantom{7}} = 9\)
\(9  2 = \boxed{\phantom{7}}\)
Student Response
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Activity Synthesis
 Invite previously identified students to share.
 Display the equations:
 \(2 + 9 = \boxed{\phantom{11}}\)
 \(9  2 = \boxed{\phantom{7}}\)
 \(2 + \boxed{\phantom{7}} = 9\)
 “Which question does each of these equations represent? How do you know?”
Lesson Synthesis
Lesson Synthesis
Write \(3 + \boxed{\phantom{7}}= 10\)
"Today we wrote equations to match story problems. Some of the equations had an unknown value. How could you find the unknown value in this equation?"(I could count on from 3 until I got to 10. I could subtract \(103\).)
Cooldown: Beans and Rocks (5 minutes)
CoolDown
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