Y.7 Match word problems to addition sentences - add ones to two-digit numbers
What is a word problem?
A word problem is a short story that uses words and numbers to ask a math question. The story tells about people, things, or actions. At the end, you must find the answer by adding, subtracting, or doing another math step.
- “Mia has 23 stickers. Her friend gives her 5 more stickers. How many stickers does Mia have now?”
This story has numbers (23 and 5) and asks a question. We need to add to find the total number of stickers.
In a word problem, look for clue words that tell you what to do. Words like “in all,” “total,” “together,” and “more” often mean you should add.
What is an addition sentence?
An addition sentence is a math equation that shows two or more numbers being combined. It uses a plus sign (+) and an equals sign (=). It looks like this: 23 + 5 = 28.
- 14 + 3 = 17
- 32 + 6 = 38
- 47 + 2 = 49
The number before the plus sign and the number after it are called the addends. The answer after the equals sign is the sum.
Ones and two-digit numbers
A two-digit number has a tens place and a ones place. For example, the number 34 has 3 tens and 4 ones. A one-digit number has only a ones place, like 7 or 2.
When we add a one-digit number to a two-digit number, we only change the ones place. The tens place stays the same.
- Start with 23 (2 tens and 3 ones). Add 5 ones. 3 ones + 5 ones = 8 ones. The answer is 28.
- Start with 41 (4 tens and 1 one). Add 7 ones. 1 one + 7 ones = 8 ones. The answer is 48.
If the ones add up to 10 or more, we form a new ten. For example, 25 + 5 = 30. 5 ones + 5 ones = 10 ones, which is 1 ten and 0 ones. So 2 tens + 1 ten = 3 tens, or 30. We call this "making a ten."
Matching word problems to addition sentences
To match a word problem to an addition sentence, you must find the numbers in the story and decide how they combine. The addition sentence must match the story’s numbers and the question being asked.
- Word problem: “Leo reads 33 pages of his book. He reads 6 more pages before dinner. How many pages does he read in all?”
- Addition sentence: 33 + 6 = 39
The story has 33 and 6. The question asks for the total. Adding 33 + 6 gives 39, which matches the story.
Always check that the addition sentence uses the same numbers from the story and in the correct order. The two-digit number usually comes first.
Steps to match a word problem
Follow these steps to match any word problem to an addition sentence. Practice these steps until they feel easy.
- Read the whole problem carefully. Understand the story.
- Find the numbers. Look for the two-digit number and the one-digit number.
- Look for clue words. Words like “in all,” “total,” “altogether,” or “combined” tell you to add.
- Write the addition sentence. Put the two-digit number first, then the plus sign, then the one-digit number. Then write the equals sign and the sum.
- Check your work. Does your sum make sense with the story?
Sometimes the word problem does not use the word “total.” It might ask, “How many are there now?” That still means you need to add.
Example 1: Adding ones without making a new ten
This example shows a word problem where the ones add up to less than 10. The tens place does not change.
“A bus has 42 people on it. At the next stop, 7 more people get on. How many people are on the bus now?”
42 + 7 = 49
The story begins with 42 people. Then 7 more join. To find the new total, add 42 + 7. 2 ones + 7 ones = 9 ones. The 4 tens stay the same. The sum is 49.
When the ones sum is less than 10, you simply write the new ones digit. The tens digit stays exactly the same.
Example 2: Adding ones that make a new ten
This example shows what happens when the ones digits add up to 10 or more. You must form a new ten.
“Elena collects 28 seashells. She finds 5 more seashells at the beach. How many seashells does she have in all?”
28 + 5 = 33
Start with 28 (2 tens and 8 ones). Add 5 ones. 8 ones + 5 ones = 13 ones. 13 ones is 1 ten and 3 ones. Add the 1 ten to the 2 tens to make 3 tens. The sum is 33.
When you make a new ten, the tens digit increases by 1. This is an important first-grade math skill. Practice with numbers like 17+4, 26+7, and 39+2.
More practice examples
Let’s look at several word problems and the addition sentences that match them. Read each one and see how the numbers fit together.
“A farmer has 53 apples. He picks 4 more apples from the tree. How many apples does he have now?”
Addition sentence: 53 + 4 = 57
“There are 36 children in the park. 8 more children come to play. How many children are in the park altogether?”
Addition sentence: 36 + 8 = 44 (6 + 8 = 14, so 3 tens + 1 ten = 4 tens, 4 ones)
“Jenny reads 21 pages on Monday. She reads 9 pages on Tuesday. How many pages did she read in total?”
Addition sentence: 21 + 9 = 30 (1 + 9 = 10, so 2 tens + 1 ten = 3 tens, 0 ones)
In example C, 21 + 9 = 30. Notice the sum is a two-digit number ending in zero. This happens when the ones add up to exactly 10.
Common clue words for addition
Certain words and phrases in a word problem signal that you should add. Learning these words helps you match problems to addition sentences quickly.
- in all — “How many toys are there in all?”
- altogether — “How many students are there altogether?”
- total — “What is the total number of fish?”
- sum — “Find the sum of 24 and 5.”
- more — “She picks 3 more flowers.”
- plus — “23 plus 6 equals what?”
- and — “He has 44 pennies and 7 nickels.”
- combined — “How many crayons combined?”
Sometimes a word problem does not use these exact words. You must think about the action. If something is being added to a group, you should add.
How to check if your addition sentence matches
After you write an addition sentence, you should check it against the word problem. This makes sure you did not misread the story.
- Does the addition sentence use both numbers from the story?
- Is the two-digit number first? (It should be, because the story starts with that amount.)
- Does the sum answer the question that the story asks?
- If you add the ones, does the total match the sum’s ones digit?
- If you made a new ten, does the tens digit show that?
Checking your work is a good habit. It helps you catch small mistakes.
Writing your own word problems
One way to get better at matching is to write your own word problem for an addition sentence. This helps you understand how stories and math connect.
Take the addition sentence 62 + 5 = 67. Here is a word problem that matches: “Luis has 62 baseball cards. His brother gives him 5 more. How many baseball cards does Luis have now?”
Try writing a story for 44 + 8 = 52. Think about something you might collect or count.
When you write your own problem, make sure the numbers are in the correct order. The two-digit number is the starting amount, and the one-digit number is what gets added.
Extra practice: Match the problem to the sentence
Here are three word problems. Below each, choose the correct addition sentence. The answers are at the bottom of this box.
“Sofia bakes 24 cookies. She bakes 6 more cookies. How many cookies did she bake in all?”
A) 24 + 6 = 30
B) 24 + 6 = 29
C) 20 + 6 = 26
“There are 51 birds in the tree. 9 more birds fly to the tree. How many birds are in the tree now?”
A) 51 + 4 = 55
B) 51 + 9 = 60
C) 51 + 9 = 61
“A jar has 37 marbles. You put 2 marbles in. How many marbles are in the jar altogether?”
A) 37 + 2 = 39
B) 37 + 3 = 40
C) 30 + 2 = 32
1: A, 2: B, 3: A
In problem 2, 51 + 9 = 60. 1 + 9 = 10, so 5 tens + 1 ten = 6 tens. That is how we get 60.
Using drawings to help match
Sometimes drawing a picture can help you understand the word problem and choose the right addition sentence. You can draw circles or use base-ten blocks.
Word problem: “Tom has 14 crayons. He buys 8 more crayons. How many crayons does he have in total?”
Draw 1 ten stick and 4 dots for 14. Then draw 8 more dots. Group the dots: 4 + 8 = 12. That means 1 ten + 1 new ten (from the 12) + 2 ones = 22. The addition sentence is 14 + 8 = 22.
Drawing is a great tool if you feel stuck. It shows you what is happening in the story.
Remember the goal
The goal is to read a story, find the numbers, and write the addition sentence that matches. This skill helps you solve real-world problems.
If you have 26 dollars and you earn 5 more dollars doing chores, you can use addition to find out you have 31 dollars. That is matching a word problem (your chore story) to an addition sentence (26 + 5 = 31).
Keep practicing with different word problems. Soon you will be able to match them without even thinking hard!
Common Core alignment: CCSS.MATH.CONTENT.1.NBT.C.4 – Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.
Notes for teachers
This free lesson is aligned with CCSS.MATH.CONTENT.1.NBT.C.4. Use it for whole-class instruction, independent practice, or homework. The lesson focuses on matching word problems to addition sentences when adding a one-digit number to a two-digit number. It covers both cases: with and without composing a new ten.
All content is 100% free, student-safe, and designed for classroom and home use. Encourage students to read each word problem carefully and look for clue words. Drawing base-ten blocks can be a helpful support for students who need extra scaffolding.