Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.
Measurement Topic
This standard is reported on the report card in these quarters as follows:
2nd Grade Students Learning 2nd Grade Standards
Quarter 1
Quarter 2
Quarter 3
Quarter 4
Report Card Measurement Topic: Adds and subtracts to solve word problems
Report Card Measurement Topic: Adds and subtracts to solve word problems
Report Card Measurement Topic: Adds and subtracts to solve word problems
1st Grade Students Learning 2nd Grade Standards
Quarter 1
Quarter 2
Quarter 3
Quarter 4
Report Card Measurement Topic: Adds and subtracts to solve word problems
Report Card Measurement Topic: Adds and subtracts to solve word problems
Report Card Measurement Topic: Adds and subtracts to solve word problems
About the Math
Skills and concepts below are learning goals for this standard.
Represent word problems using physical models, drawings, and number lines.
Students must represent problems to develop an understanding of them and how to solve them. Various representations are needed for deep understanding. These representations must be connected to the problem and to equations. Bar diagrams and similar drawings are good choices for representing the relationships within a problem.
Solve word problems with unknown numbers in different positions (e.g., 5 + _ = 13, + 8 = _)
As students develop an understanding of problems, students should connect and then write equations that can be used to solve the problems. Those equations should accurately reflect the problem type with the unknown in an accurate position.
Explain why an operation is needed to solve a word problem.
Students must explain why an operation is needed to solve a problem. It connects to their representations and making sense of the problem in general. Joining, combining, and adding to are clearly addition situations. Subtraction situations can be solved with either operation. Also, know that 2nd-grade students should work with comparison problem types (John has 4 more apples than Stephanie who has 6. How many more apples does John have?)
Identify the first step in a two-step word problem.
Write an equation to represent a one-step word problem.
When solving a two-step problem, students should identify what needs to be done first. This is developed through an understanding of what the problem is asking and how it can be represented. Students should then write and connect an equation to the first step.
Identify the second step in a two-step word problem.
Write two equations to represent a two-step word problem.
A second equation can then be written to solve the second step of a problem. Note that the second step can be identified before the action of finding the solution to the first step. Again, students should represent the second step and write an equation for it. Students DO NOT need to write a single equation for both steps in the problem.
Determine if an answer is reasonable by estimating and/or reflecting on the steps taken to solve the problem.
Determining if an answer is reasonable for a two-step problem is more complex than simply estimating the result. Determining if a solution to a two-step problem relies more on questions that ask if it makes sense in the context of the understanding. For example, "does it make sense that my solution is greater than all of the numbers in the problem because I added and added again?" is a good question to determine reasonableness in a two-step problem.
These tasks can be used with small group or whole group instruction.
Gather base ten blocks. Students could also chose to draw a number line. Pose word problems to the students. Have students initially discuss what is happening in the word problem-- making meaning about what is happening in the problem is critical. Pose a question such as what would be a reasonable answer and why. Then have students to solve. To debrief the math thinking, have students share out how they solved the problem and make connections between different student representations.
Pose "result unknown" problems and ask students to focus on the action in the problem. Use more simplistic or friendly numbers as we want students to make meaning of the problem before becoming overwhelmed with the numbers. For each problem, provide students with 2 equations and ask which one matches the story problem and why.
I made a total of 52 cookies and I gave 14 cookies to my neighbor. How many cookies do I still have? (result unknown)
Jabril came to school with 48 pencils. Some of his friends didn’t have a pencil, so he gave some of his pencils away. He now has 20 pencils. How many pencils did he share with his friends? (result unknown)
Jackie picked some blackberries. Her kids ate 29. She now has 52. How many blackberries did Jackie pick? (change unknown)
Bill caught 23 fish. He caught some of the fish on Monday and some on Tuesday. What are some fish amounts for each day that could have happened? What is another possible solution?
Mrs. Coleman’s class is going on a field trip! The bus has 40 seats, but 10 seats are empty. How many people are on the bus.
Alliyah had 2 quarters, 2 dimes, 1 nickel, and 5 pennies. Brayden had 1 quarter, 4 dimes, 3 nickels, and 4 pennies. Who has more money? Prove it using your coins, a number line, and or a hundreds chart.
Mrs. Smith's 2nd grade class is having a car race! Hank's car rolled 51 inches. Rosa's car rolled 38 inches. Who won the race? How many fewer inches did Rosa's car roll? *Consider having your students participate in their own car races!
SLIDE-BASED TASKS
These links are HCPSS created instructional tasks. These tasks are provided in Google slides. These tasks should be used for inspiration and resources, but instruction should start with students having the opportunity to engage with the math first (often involving physical and/or visual models) followed by discussion and explicit instruction to ensure student understanding.
These links provide instructional ideas connected to this standard. [NOTE: NCTM membership required for access to Illuminations lessons.] Links to an external site.
These publications have been provided for each school. They are typically stored in team closets or the media center. Check with your team leader if you cannot find them.
Print Resources
Book Thumbnail
Book Title
Grade
Pages
Teaching Student-Centered Mathematics
K-3
165 (Ten-Frame Adding and Subtracting, Activity 6.1)
Hands-On Standards
1-2
26-27 (Addition Sentences) 28-29 (Addition Doubles) 30-31 (Explore Counting Back) 32-33 (Comparing Subtraction) 34-35 (Subtraction Sentences) 36 (Connecting Addition and Subtraction) 44-45 (Addition without regrouping) 46-47 (Addition with regrouping) 48-49 (Subtracting without regrouping) 50-51 (Subtracting with regrouping)
These print resources can be used during independent or center time. These resources could also be used as lesson seeds.
INDEPENDENT PRACTICE/HOMEWORK/ASSESSMENT
These resource sheets can be used for independent practice, homework, or assessment. They are intended to reinforce procedures and concepts. They should not be used as a source of direct instruction or whole-group practice.
Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.
Measurement Topic
The standard is reported on the report card through these measurement topics. Expand the measurement topic for a description of what students who meet expectation are able to do.
2nd Grade Students Learning 2nd Grade Standards by Measurement Topic
Model accurately addition and subtraction result unknown problems within 100 using objects, drawings and/or equations.
Explain how the representation (i.e. objects, drawings and/or equations) connects/matches to the result unknown story problem.
Solve addition and subtraction result unknown problems accurately within 100.
Quarter 2
Model accurately addition and subtraction comparison and result, change, and start unknown problems within 100 using objects, drawings, and/or equations.
Explain how the representation (i.e. objects, drawings, and/or equations) connects/matches to the comparison or result, change, and start unknown story problem.
Solve comparison and result, change, and start unknown word problems accurately within 100 with the unknown number in different positions.
Quarter 3
Use physical models, drawings, number lines and/or equations to accurately represent two-step word problems.
Solve two-step word problems.
1st Grade Students Learning 2nd Grade Standards by Measurement Topic
Model accurately addition and subtraction result unknown problems within 100 using objects, drawings and/or equations.
Explain how the representation (i.e. objects, drawings and/or equations) connects/matches to the result unknown story problem.
Solve addition and subtraction result unknown problems accurately within 100.
Quarter 2
Model accurately addition and subtraction comparison and result, change, and start unknown problems within 100 using objects, drawings, and/or equations.
Explain how the representation (i.e. objects, drawings, and/or equations) connects/matches to the comparison or result, change, and start unknown story problem.
Solve comparison and result, change, and start unknown word problems accurately within 100 with the unknown number in different positions.
Quarter 3
Use physical models, drawings, number lines and/or equations to accurately represent two-step word problems.
Use the links below to access a task for this standard as well as student work samples that are examples of what it might look like for a student who MEETS EXPECTATIONS, is MAKING PROGRESS, and/or is MAKING LIMITED/NO PROGRESS.
