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.
Learning Targets (I can)
Represent word problems using physical models, drawings, and number lines.
Solve word problems with unknown numbers in different positions (e.g., 5 + _ = 13, + 8 = _)
Explain why an operation is needed to solve a word problem.
Identify the first step in a two-step word problem.
Write an equation to represent a one-step word problem.
Identify the second step in a two-step word problem.
Write two equations to represent a two-step word problem.
Determine if an answer is reasonable by estimating and/or reflecting on the steps taken to solve the problem.
About the Math
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 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 links provide ideas for lessons connected to this standard. They may support small group instruction or whole group collaborative investigations. They are intended to serve as a starting point for planning.
Rigorous mathematics instruction balances the teaching and learning of conceptual understanding, procedural understanding, and the application of mathematics standards. Below are prompts for applying rigor in your classroom. They may support small group instruction or whole group collaborative investigations. They are intended to serve as a starting point for planning. See the Increasing Rigor page for more information.
I made a total of 52 cookies and I put them randomly on 2 plates. I gave 14 cookies to my neighbor from the first plate but there were still 17 on that plate. How many cookies are on the second plate?
The difference is 23, create a story problem that can be solved by subtracting two 2-digit numbers with this difference.
Jackie picked some blackberries. Her kids ate 29. She now has 52. How many blackberries did Jackie pick?
Bill caught 23 fish. He caught some of the fish on Monday, some on Tuesday, and some on Wednesday. Each day he caught more than the day before. 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! Each student will be bringing one adult. There will be as many adults riding as children. The bus has 40 seats, but ten seats are empty. How many adults and children are riding the bus if they each have their own seat? Write your answer in a number sentence. Are there an odd or even number of adults and children?
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 32 pencils. How many pencils did he share with his friends?
+++ Indicates recently created HCPSS instructional tasks. These tasks are provided in Google slides. When selected, a copy of the file is added to your drive for classroom use.
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.
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 links provide ideas for lessons connected to this standard. They may support small group instruction or whole group collaborative investigations. They are intended to serve as a starting point for planning. [NOTE: NCTM membership required for access to Illuminations lessons.]
These resource sheets can be used for independent practice or homework. They are intended to reinforce procedures and concepts. They should not be used as a source of direct instruction or whole-group practice.
Represent word problems using physical models, drawings, and number lines.
Solve word problems with unknown numbers in different positions (e.g., 5 + _ = 13, + 8 = _)
Explain why an operation is needed to solve a word problem.
Identify the first step in a two-step word problem.
Write an equation to represent a one-step word problem.
Identify the second step in a two-step word problem.
Write two equations to represent a two-step word problem.
Determine if an answer is reasonable by estimating and/or reflecting on the steps taken to solve the problem.
Learning targets identify what students should be able to do. The resources below can be used to measure student understanding of the standard. The recording sheet can be used to collect data. The rubric can be applied to any task.
These tasks align with the learning targets for the standard. They can be combined with other tasks for extended assessment opportunities. Teachers/students are not expected to complete all these tasks.
