Word problems is one of the biggest units I taught in 2nd grade. Word problems are a key skill and should be taught and reviewed throughout the entire year.
What First Graders Should Know
Students entering the 2nd grade should have the following skills:
- Solve word problems up to 20 using addition and subtraction;
- Types of word problems: adding to, taking from, putting together, taking apart, and comparing with unknowns in all positions.
At the beginning of the year, it’s beneficial to evaluate students’ understanding of adding and subtracting to 20. If they can add and subtract to 20 fluently, then move on to numbers 20-50. If there are a large group of students who still struggle, take some time to review the 1st-grade word problem standard 1.OA.A.1.
Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions.
The only difference between the 1st and 2nd grade standards is that 1st grade solves up to 20, while 2nd grade solves up to 100. So if you do need to review 1st grade standards, you’re still covering the practical concepts of the standard, just within a limited number range.
How much time you spend on review will depend on the levels of your students. If your students need it, it is helpful to allocate the entire first cycle of teaching word problems to review, which would put this at about two weeks. That may seem like a lot of time to review, but keep in mind that during this time you are teaching students about the different types of word problems and the problem-solving process. Working with numbers under 20 makes the computation more manageable and allows students to focus on learning the types of problems and the problem-solving process.
Preparing for the Lesson:
- Create a poster to model a word problem. You can use my poster word problems from my 2nd Grade Word Problem packet, or you can write your own.
- Print and laminate the Problem-Solving Process posters. Attach them to a ribbon and hang them in a convenient place where all students can see them. Make sure you can easily access the poster or move it for the lessons.
- Begin creating a “Types of Word Problems” poster. For day 1, you should include “Adding To” word problems. You will add skills to this poster as you introduce them to the students.
- Prepare one group word problem posters for each group for the students to use during group work. You can write your own problems or print one of the “adding to” poster problems in my word problem packet. A great way to engage your students is to write word problems with their names. I’ve also made my word problem packet editable, so you can type your class list and the problems will autogenerate with your class list!
Introduce the standard. Tell students that you are starting by reviewing word problems they learned in first grade. Today students will work on “Adding to” word problems. “Adding to” problems mean you start with a number of something, and more gets added to your group.
Show the word problem poster. Explain that you are going to show them how to solve this problem.
- Show the problem-solving process poster. Point to the fir
st step. Explain that first, we need to read the problem and visualize it. Then model the skill by reading the problem and then explaining the picture you see in your mind.
- “Sweet Delights had 33 strawberry cupcakes. They baked 6 more. How many strawberry cupcakes does Sweet Delights have now?”
- I am imagining a cupcake shop with trays of cupcakes on the counter. They have a tray with 33 cupcakes, which is 3 rows of 10 and 1 row of 3. Next, I am imagining the baker coming out with 6 more strawberry cupcakes and adding them to the row of 3.
- Now I have visualized the problem (point to the first step on the process chart).
Next, I am going to retell the problem.
- Cover up the problem with your hands and retell the story to your class. Ask, “Did I get the gist of the problem?”
Now that I have retold the problem, I know I comprehend it, so I am ready to circle and underline key words. Model circling the numbers in the problem and underlining the key words.
- “Sweet Delights had (33) strawberry cupcakes. They baked (6) more. How many strawberry cupcakes does Sweet Delights have now?”
- Check! I have circled and underlined the key words and numbers that will help me solve the problem.
Next, I am going to solve the problem using a strategy. For this problem, I am going to draw a picture.
- Draw a cupcake tray with 3 rows of ten circles and one row of 3 circles using a black marker.
- “I have the 33 cupcakes Sweet Delights started off with. Now, I am going to add 6 more.” Draw 6 pink circles on the tray.
- Now I have all of the strawberry cupcakes, so to answer the question “How many strawberry cupcakes does Sweet Delights have now?” I am going to count all of the cupcakes. I have 39 cupcakes.
*Note* In the beginning of 2nd grade, drawing pictures and diagrams to solve problems is an appropriate method for solving problems. As students learn the problem-solving process, numbers will get more difficult and students should move to more efficient strategies.
Now that I have solved the problem, I am going to write an equation.
- This was an “adding to” problem, so I know this is an addition equation.
______ + _______ = ________
- Sweet Delights started with 33 strawberry cupcakes, so I know that is going to be the first number in my equation.
- Then, they added 6 more strawberry cupcakes, so I know that is going to be my second number.
- I know that after they added 6 cupcakes, they had a total of 39 strawberry cupcakes, so 39 is what comes after the equal sign.
The next step says to label my answer.
- What does 39 mean? 39 puppies? 39 children? 39 pencils? No, it means 39 strawberry cupcakes.
Now that I have my answer, you probably think I’m done, right? No! Math is awesome because we know there is often a right or wrong answer. There are lots of chances for making mistakes, but if we check our work, we will be much more confident we didn’t make a mistake.
- Model checking your work by using a different strategy. The strategy could be using manipulatives, doing another picture, or counting on your fingers. After you’ve modeled checking your work, put a big check next to the answer to show this step is complete.
Now students will have a chance to try the problem-solving steps with an “adding to” problem in their groups. They will make their own poster with their groups showing all of their work. Students love to work on chart paper or large construction paper.
(Note: It is important to set expectations for group work, including all students participate and help each other. When the teacher comes over to ask a question, all group members should be able to answer.)
As each group works on their problem, rotate to ask questions to check for understanding. If students make mistakes, don’t tell them directly. Instead, expect students to “catch it” when they check their work. After students have completed all of the steps, review their poster and allow them to go over their work in markers, so it stands out. Then, I select one group to share with the class how they solved the problem.
Next, students work independently on one of the word problems from my word problem packet. Pull students who are struggling into quick one on ones. Reteaching in small groups can also be effective, but it is usually sufficient to have students work independently while you monitor and ask questions to guide them in the right direction. Don’t forget that the goal is to get them to be more independent!
Right before the end of the work period, walk around the room one more time to observe students working. Select one student who has followed the steps and gotten the correct answer to share how they solved the problem. (Note: At the beginning of the unit I liked to purposefully select students who “get it”, but as the unit progresses, I think it is important to have students share who may have skipped a step or gotten the wrong answer.
At the beginning of this unit, I would only give students 1-2 problems to practice each day. This is of the utmost importance. Less is more because the goal is to get students to master the problem-solving process. Giving students too many problems early on can overwhelm their learning process and put too much focus on getting answers just to get it done.
Start by collecting all independent work. Then have the selected student share how they solved the problem. Initially, it is important to have the student share the whole process, but as the unit and year continue and students have mastered the process, you can shorten this by having a student share one step they did.
To ensure students have mastered the problem solving strategy, I always gave a short quiz on the last day or before beginning the next strategy. My word problem packet also includes short, 2 question quizzes so ensure your students are on track.
Building on the Skills:
Continue this routine each day, going through a different type of story problem. Here is a sample schedule:
|Day 1||Adding To|
|Day 2||Taking From|
|Day 3||Putting Together|
|Day 4||Taking Apart|
|Day 5 & 6||Comparing|
|Day 7 & 8||Unknown|
|Day 9 & 10||Multistep|
|Day 12 & 13||Review All Types|
Adding to, taking from, putting together, and taking apart problems tend to be easier for students to grasp, because they have the most exposure to these. Comparing, unknown, and multistep problems are much more challenging, so you may need a few days to focus on these.
After teaching all of the typse of problems, I assess students on 2.OA.A.1 with the number range I taught. You can find assessments for 20-50, 50-100, and 100-1,000 in word problem packet.
The Big Picture:
Throughout the year, use this same process to build on student’s problem-solving skills.
When students are learning to add and subtract to 100, do another unit on problem-solving with numbers to 100. When students are learning to add and subtract to 1,000, you can expand on the skills and do a problem-solving unit with numbers to 1,000, despite the standard only going to 100.
- I do place an emphasis on the problem-solving process, but, as students begin to understand the steps, it is important to give them flexibility. Everyone’s brain works differently, and we may do some steps in a different order. For example, it may make more sense for some students to write their equation before they solve the problem, but others may need to work the problem out first. Some students may circle key words while they read the problem because this helps them comprehend. Remember to remain flexible with students and don’t be afraid to suggest different approaches to help them grasp the concepts.