Are your students struggling with missing addend word problems? Do they find themselves stumped when trying to solve these tricky math problems? Missing addend word problems can be frustrating and time-consuming, but with the right strategies, they can become a breeze. By understanding the key concepts behind these problems and implementing efficient problem-solving techniques, you can dramatically improve your student’s success.
- ☀Download this BONUS Guide with everything you need to cultivate a positive classroom community.
- ➕Includes definitions, lesson ideas, mindset surveys for students and teachers, and printable posters.
- 🧠💪Research shows a link between a growth mindset and math success. Kids with a growth mindset about their abilities perform better and are more engaged in the classroom.
- 👉Includes everything you need to start cultivating a more positive math classroom and students who love math.
- Download and get started today! Click here to download the Bonus Mindset Guide & Survey.
Students struggle with missing addend problems because they tend not to read and understand what the problem is asking them to solve. Many times, students just take the 2 numbers in the problem and add or subtract them, so how can we help students master these types of problems?
What are Word Problems?
A word problem is a few sentences describing a ‘real-life’ scenario where a problem needs to be solved through a mathematical calculation.
A one-step equation is an algebraic equation you can solve in only one step. The common core lists several problem situations that are taught beginning in Kindergarten.
Missing Addends
A missing addend word problem has one of the addends missing in an addition problem. Addends are the numbers you add or put together to get the sum or answer in an addition problem. Addend + Addend = Aum.
Word Problem Example
Paula has 16 tickets for the raffle. She has 8 fewer than Mark. How many tickets does Paula have?
Word Problem Standards with Missing Addends
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.
2.OA.A.1 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.
Teaching Word Problems for Addition and Subtraction
1st Grade Word Problems
At the beginning of the first grade, review situations that were taught in kindergarten and increase the number to 20. Over time, introduce the other situations for students to model. Have students describe what is happening in the problem and make a plan for solving the problem. In addition, they should identify what they are looking for in each problem situation. For example, the number of apples.
Students solve problems using materials such as counters, five and ten frames, part-part-whole tables, and number lines to model various situations. In addition, they begin to use drawings to represent what is happening in the problem. Model writing equations that describe the student actions with the expectation that they will begin to use symbols to show their work when ready. Give students opportunities to say the equation orally and then in writing.
Facilitate discussions in which students explain their thinking with models and representations. Ask questions such as, “How did you know? What operation did you use? Does it Make Sense?” In addition, allow them to explain their reasoning in partners, in small groups, and to the class. Encourage students to use precise mathematical language and appropriate vocabulary.
2nd Grade Word Problems
This standard extends the Kindergarten and Grade 1 one-step word problem standards. Students should continue to use linking cubes, place value blocks, ten frames, and counters to model problems. When solving problems, some students may be ready to move from the concrete stage to the representational stage.
Students may use materials or draw pictures to determine a strategy for solving a problem. As students work with concrete materials to solve problems, teachers should help students see the connection between pictorial representations and abstract (equations) representations.
Teachers should continue to provide students with experiences using all the problem structures. Eventually, move to two step word problems with smaller numbers and both operations being the same. Then, use larger numbers and both addition and subtraction within the same problem.
Begin with using problems with small numbers, so the focus stays on understanding the problem situations and finding strategies to solve the problem instead of extending computational skills. Eventually, increase the range of numbers in the problem to a total (sum) of 100.
In addition, opportunities for students to explain their strategies for solving problems and make connections between strategies are essential. This allows students to extend their thinking and decide if they are using the most efficient strategy.
To read more on 2 Step Word Problems….What’s the Best Proven Way to Teach Word Problems with Two Step Equations?
Word Problem Structures
This is a breakdown of the word problem structures taught in 1st grade and then continued into 2nd grade.
1st Grade Word Problem Structures
- Add to- change unknown (7 add some more equals 9: 7 + ? = 9)
- Two frogs were sitting on the grass. Some more frogs hopped there. Then there were five frogs. How many frogs hopped over to the first two? 2 + ? = 5
- Add to- start unknown (have some add 4 more equals 9: ? + 4= 9)
- Some bunnies were sitting on the grass. Three more bunnies hopped there. Then there were five bunnies. How many bunnies were on the grass before? ? + 3 =5
- Take from- change unknown ( 9 take away some equals 7: 9 – ?=7)
- Five apples were on the table. I ate some apples. Then there were three apples. How many apples did I eat? 5 – ? = 3
- Take from- start unknown ( have some take away 4 equals 3: ? – 4=3)
- Some apples were on the table. I ate two apples. Then there were three apples. How many apples were on the table before?? -2 = 3
- Put together/ take apart- addend unknown (take 7 apart: 7= 3 + ?)
- Five pears are on the table. Three are red, and the rest are green. How many pears are green? 3 + ? = 5, 5-3 = ?
- Comparison- difference unknown, smaller unknown, bigger unknown
- Difference unknown: Larry has 5 apples. James has 8 apples. How many more apples does Larry have than James? 5 + ? = 8 8 – 5 = ?
- Bigger unknown: Larry has 4 fewer oranges than James. Larry has 6 oranges. How many oranges does James have?
- Smaller unknown: Larry has 6 fewer apples than James. James has 9 apples. How many apples does Larry have?
2nd Grade Word Problem Structures
- Continue to provide students with experiences using all the problem situations.
Link to Addition and Subtraction Problem Structure Table
Word Problems of Addition and Subtraction Strategies
Using Ten Frames and Double Ten Frames
A ten frame is a rectangle with ten equal spaces. It has five spaces on top and five on the bottom. You often find the ten frames positioned horizontally and filled with counters placed from left to right. A double ten frame is 2 ten frames put together to show up to 20.
Ten frames are a fantastic tool used in kindergarten and first grade to help build an understanding of counting, place value, adding, subtracting, and more. You use counters or math manipulatives to represent word problems on the frame. Check out this link to find a free Ten Frames Template. Ten Frames Free Printable.
Read more about using ten frames here…Why Using Ten Frames for Math to Develop Understanding is Effective?
Using Part-Part-Whole Mats
The part-part-whole model is a pictorial representation of a problem that helps students see the relationship between a “whole” and its components.
The part-part-whole mat shows that you know some information but still need to find additional information. The bar can be split into as many parts as you need, depending on the information you’ve been given. The whole or any of the parts can be missing.
In addition, children using this model will see the relationship between the whole number and its parts, helping learners to make the connections between addition and subtraction.
This is another valuable tool in modeling word problems. Check out this link to find a free Part-Part-Whole Template. Part- Part-Whole Mat
Read more about using the part-part-whole strategy here…How to Use the Powerful Part-Part-Whole Strategy to Improve Number Sense.
Real-World Connections & Math Literature
Using real-world situations or situations from literature books will help students visualize what is happening in the word problems. Then, students can act out the problem or use counters to model what is happening.
Problem Solving Steps in Math
Students are more successful when using these 4 problem-solving steps in math. This helps them think about the problem and make a plan before even solving the problem. Then, after solving the problem, check if their answer makes sense.
Step One: Understand
- Read and think about the problem.
- Circle the needed information in the problem.
- Underline the question in the problem.
- Write an answer stem sentence. There are ____ pages left to read.
Step Two: Plan
- Make a plan to solve the problem.
- What strategy will you use? (draw a picture, work backward, look for a pattern, create a table, bar model)
- What math tools do you need?
Step Three: Do
- Solve the problem.
- Show your work to solve the problem.
Step Four: Check
- Answer the question and check your work.
- Write the answer into the answer stem.
- Does your answer make sense?
- Check your work using a different strategy.
Understanding Missing Addend Word Problems
Missing addend word problems are a specific type of mathematical problem that requires students to find an unknown number in an addition equation. These problems often present a scenario in which two known quantities are added together to achieve a total, and one of those quantities is missing.
For example, a problem might state, “Emma has 7 apples, and she needs a total of 10 apples. How many more apples does she need?” Here, the unknown quantity—the number of apples Emma still needs—is the missing addend.
Importance of Mastering Missing Addend Word Problems
Mastery of missing addend problems lays a strong foundation for understanding subtraction, as recognizing that subtraction is the inverse of addition is essential.
Moreover, the ability to solve missing addend word problems is a vital life skill. In real life, individuals often encounter situations where they need to determine how much more of something they require to reach a goal.
Whether it’s budgeting finances, planning events, or even cooking, knowing how to identify and calculate missing quantities is an everyday necessity. Therefore, teaching students to master these problems is not just about passing tests; it’s about preparing them for real-world applications of mathematics.
Common Types of Missing Addend Word Problems
When it comes to missing addend word problems, there are several common types that students may encounter.
Example 1:
One type is the “how many more” problem. In these scenarios, students are given a total and one known quantity, and they must find out how much more is needed to reach that total.
For example, a problem may state, “There are 15 students in the classroom, and 8 are boys. How many girls are in the classroom?” This type of question requires students to determine the missing addend to complete the total number of students.
Example 2:
Another common type involves “part-part-whole” problems, where students are asked to determine the missing part when given a whole and one part. For instance, if a problem states, “A jar contains some marbles. If there are 12 red marbles and a total of 20 marbles in the jar, how many are not red?”
This problem helps students understand how different parts relate to a whole, reinforcing the concept of addition and subtraction within the context of the problem.
Problem Types:
- Add to- change unknown (7 add some more equals 9: 7 + ? = 9)
- Two frogs were sitting on the grass. Some more frogs hopped there. Then there were five frogs. How many frogs hopped over to the first two? 2 + ? = 5
- Add to- start unknown (have some add 4 more equals 9: ? + 4= 9)
- Some bunnies were sitting on the grass. Three more bunnies hopped there. Then there were five bunnies. How many bunnies were on the grass before? ? + 3 =5
- Take from- change unknown ( 9 take away some equals 7: 9 – ?=7)
- Five apples were on the table. I ate some apples. Then there were three apples. How many apples did I eat? 5 – ? = 3
- Take from- start unknown ( have some take away 4 equals 3: ? – 4=3)
- Some apples were on the table. I ate two apples. Then there were three apples. How many apples were on the table before?? -2 = 3
Step-by-Step Approach to Solving Missing Addend Word Problems
The first step is to read the problem carefully. Students should take their time to identify the important information presented in the scenario. It’s crucial to underline or highlight clue words, such as “total,” “more,” or “fewer,” as these will guide them in formulating the appropriate mathematical equation. Understanding the context is vital for translating the problem into a solvable form.
Next, students should create a model to represent the problem. Using a part-part-whole mat is a great tool to represent the problem. Then, use that information to write an equation. Finally, students should solve the equation and put their answer back into the word problem to make sure it makes sense.
Effective Strategies for Solving Missing Addend Word Problems
Employing effective strategies can help students enhance their ability to solve missing addend word problems efficiently. One of the most powerful techniques is the use of visual aids.
For example, drawing pictures, using number lines, or creating bar models can provide a tangible representation of the problem, making it easier to grasp the relationships between the numbers involved.
Another helpful strategy is to encourage students to use estimation before solving the problem. By making an educated guess about the possible range of the answer, students can develop a clearer understanding of the problem’s context.
Real-life Examples of Missing Addend Word Problems
Real-life examples can greatly enhance students’ understanding of missing addend word problems by providing context to their mathematical learning. Consider a scenario involving grocery shopping. A parent might say, “We have 20 dollars for groceries, and we spent 7 dollars on fruits. How much do we have left to spend?” This situation directly applies the missing addend concept in a familiar context, helping students see the practical applications of their math skills.
Another engaging example could involve planning a birthday party. A student might encounter a problem such as, “There are 30 invitations sent out for a birthday party, and 15 have been returned. How many more invitations need to be returned?” This scenario not only uses the missing addend format but also resonates with students’ experiences, making the math more relevant and interesting.
Finally, consider a sports-related example: “A basketball team scored 80 points in a game, and 25 of those points were scored by a single player. How many points were scored by the rest of the team?” This type of problem allows students to connect with their interests and hobbies while practicing their problem-solving skills. By presenting word problems in relatable contexts, students are more likely to engage with the material and retain the concepts being taught.
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Tools and Resources for Practicing Missing Addend Word Problems
Start Unknown Word Problems Worksheets and Slides
Use these Start Unknown Word Problems Worksheet and Google Slides. Teach word problems with unknown addends with this set of 20 word problems. These practice start unknown word problems within 20 using the problem-solving steps.
Word Problems with Unknown Addends
Teach Word Problems with unknown addends with this set of 20 word problems. These practices start unknown word problems within 10 using the problem-solving steps. There are 20 Google Slides and 20 start unknown word problems Worksheets.
Addition Word Problems with Missing Addends
Teach Addition Word Problems with Missing Addends with this set of 20 word problems. These practices change unknown word problems within 20 using the problem-solving steps.
Word Problems Change Unknown
Teach Word Problems Change Unknown with this set of 20 word problems. These practices change unknown word problems within 10 using the problem-solving steps. There are 20 Google Slides, 20 Worksheets, and 5 Easel activities.
Common Mistakes to Avoid When Solving Missing Addend Word Problems
One common mistake is misreading the problem. In their rush to find the answer, students might overlook crucial information or misunderstand the question being asked. To combat this, it’s essential to encourage students to take their time while reading and to highlight or underline key phrases that indicate what is required.
Another frequent error is failing to set up the equation correctly. Students may struggle to translate the words of the problem into the proper mathematical operation.
Finally, students often neglect to check their work after arriving at an answer. In the excitement of solving a problem, they may skip the vital step of checking their answer.
Fostering a Growth Mindset Classroom
Fostering a positive mindset around problem-solving can significantly enhance efficiency. Encouraging students to view challenges as opportunities for growth rather than obstacles can help them approach problems with a more open and resilient attitude.
Reminding them that making mistakes is a natural part of the learning process can also reduce anxiety around math, allowing them to focus more on the problem-solving process rather than the fear of getting the answer wrong.
- ☀Download this BONUS Guide with everything you need to cultivate a positive classroom community.
- ➕Includes definitions, lesson ideas, mindset surveys for students and teachers, and printable posters.
- 🧠💪Research shows a link between a growth mindset and math success. Kids with a growth mindset about their abilities perform better and are more engaged in the classroom.
- 👉Includes everything you need to start cultivating a more positive math classroom and students who love math.
- Download and get started today! Click here to download the Bonus Mindset Guide & Survey.
Missing Addend Word Problems in Math
By understanding the structure of these problems, recognizing their importance, and employing effective strategies, students can confidently tackle these challenges. Engaging with real-life examples helps contextualize their learning while using tools and resources provides ample practice opportunities.
So the next time you are teaching missing addend word problems, be sure to use some of these ideas and strategies.
