Solving Word Problems with Addition & Subtraction Within 20 - 1st Grade Math

Section 1

Why Do We Solve Word Problems?

People have been using numbers to solve real-life problems for a very, very long time! Even before there were pencils and paper, people needed to count things. They counted animals, food, and friends. Let's look at how people learned to add and subtract, just like you are learning right now.

A Long, Long Time Ago

People used sticks and stones to count things. If a farmer had 5 sheep and got 3 more, he would put down 5 stones, then add 3 more stones, and count them all!

About 5,000 Years Ago

People in Egypt and Mesopotamia started writing numbers down. They drew little marks on clay tablets to keep track of how many things they had.

About 1,500 Years Ago

Mathematicians in India invented the numbers we use today — 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. This made adding and subtracting much easier!

Today — Your Turn!

Now you are learning to use these numbers to solve word problems. You are part of a big story that goes back thousands of years. How cool is that?

Word problems are little stories that have numbers in them. You read the story, figure out what is happening, and then use addition or subtraction to find the answer. This is something people need to do every single day — at the store, at home, and at school!

Section 2

The Four Big Ideas

Word problems are little stories. Every story has something happening in it. There are four kinds of things that can happen in a math story. Let's learn about each one!

Adding To 🎁

You start with some things. Then you get more. Now you have a bigger number! Example: You have 4 crayons. Your friend gives you 3 more.

Taking From 🍪

You start with some things. Then some go away. Now you have a smaller number! Example: You have 9 cookies. You eat 2 of them.

Putting Together 🧩

You have two groups. You want to know how many there are in all. Example: There are 5 red balls and 6 blue balls.

Taking Apart 🍎

You know the total. You know one part. You need to find the other part. Example: There are 10 apples. 4 are green. How many are red?

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Key Takeaway

Think of it like a toy box! Adding to is like putting toys INTO the box. Taking from is like taking toys OUT. Putting together is like pushing two piles of toys into one big pile. And taking apart is like looking at your big pile and figuring out how many are stuffed animals and how many are cars.

Section 3

See It With Pictures!

Pictures help us understand word problems. Let's look at how adding to and taking from look when we draw them. We will use circles to stand for objects — like apples, toys, or stickers!

Adding to (top) and taking from (bottom) shown with circles

In the top picture, we see adding to. The blue circles are what you start with. The green circles are what you get more of. Count them all together and you get 8!

In the bottom picture, we see taking from. You start with 9 circles. The ones with the big red X are taken away. Count what is left and you get 5!

Section 4

How to Solve Word Problems

Here is a simple way to solve any word problem. Follow these three steps every time!

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Step 1: Read the story carefully 📖

Read the whole problem. Think about what is happening. Who is in the story? What are they doing?

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Step 2: Decide — Add or Subtract? 🤔

Ask yourself: Are things coming together or going away? If things are getting bigger or joining together, you add. If things are leaving or you need to find a missing part, you might subtract.

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Step 3: Write the number sentence and solve! ✏️

Write down the numbers and the + or − sign. Then find the answer!

Let's look at the clue words that tell you what to do:

Addition Clue Words

in all • altogether • total • more • join • both

These words usually mean you need to ADD (+)

Subtraction Clue Words

left • fewer • gone • gave away • how many more

These words usually mean you need to SUBTRACT (−)

Here is what an addition number sentence looks like:

Addition

part + part = whole

Example: 6 + 7 = 13

And here is what a subtraction number sentence looks like:

Subtraction

whole − part = part

Example: 15 − 8 = 7

Section 5

The Four Types of Word Problems

Let's look at each kind of word problem more closely. For each type, we will see a little story and a picture!

Four types of word problems: adding to, taking from, putting together, and taking apart

Each box shows one type of story. Notice how putting together uses addition — you combine two groups. And taking apart uses subtraction — you know the total and one part, so you subtract to find the other part.

Type	What Happens	Do You Add or Subtract?
Adding To	You start with some. You get more.	Add (+)
Taking From	You start with some. Some go away.	Subtract (−)
Putting Together	Two groups join. How many in all?	Add (+)
Taking Apart	You know the total and one part. Find the other part.	Subtract (−)

Section 6

Let's Solve One Together!

📝

Story

Emma has 8 flowers. Her mom gives her 6 more flowers. How many flowers does Emma have in all?

Worked Example: Emma's Flowers

1
Step 1 — Read the Story 📖

Emma has flowers. Her mom gives her more flowers. We need to find out how many she has now. The words "in all" are a clue!
2
Step 2 — Decide: Add or Subtract? 🤔

Emma is getting more flowers. Things are getting bigger! This is an "Adding To" problem. We need to add.
3
Step 3 — Write the Number Sentence ✏️

8 + 6 = ?
4
Step 4 — Solve It! 🎉

Let's count up from 8. Hold up 6 fingers and count: 9, 10, 11, 12, 13, 14.

8 + 6 = 14
5
Step 5 — Say the Answer in a Sentence 💬

Emma has 14 flowers in all. Great job!

Section 7

Helpful Tips and Tricks

Here are some things that can help you solve word problems like a superstar!

Tip	Why It Helps
Draw pictures	Drawing circles or tally marks helps you see the numbers.
Use your fingers	Your fingers are always with you! Great for counting on or counting back.
Look for clue words	Words like "in all," "left," and "more" tell you what to do.
Check your work	After you solve it, read the story again. Does your answer make sense?
Use a number line	Jump forward for addition. Jump backward for subtraction.

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Key Takeaway

Think of a number line like a big ruler on the floor. When you add, you take steps forward (to the right). When you subtract, you take steps backward (to the left). The number you land on is your answer! 🦶

One thing to watch out for: sometimes a problem says "how many more" and you might think you need to add. But "how many more" usually means you need to subtract to find the difference! Always think about what the story is really asking.

Section 8

What Comes Next?

You are doing amazing! Right now, you are learning to add and subtract with numbers up to 20. But guess what? This is just the beginning! Here is what you will learn as you grow:

What You Know Now	What You'll Learn Next
Add and subtract up to 20	Add and subtract bigger numbers — up to 100 and beyond!
One-step word problems	Two-step word problems (you solve twice!)
Adding groups together	Multiplication — a faster way to add many same-size groups!
Taking apart groups	Division — splitting a big group into smaller equal groups!

Everything you learn now about adding to, taking from, putting together, and taking apart will help you with all of these new skills. You are building a strong math brain! 🧠

Section 9

Practice Time! 🌟

Now it's your turn! Try to solve each word problem. Think about what is happening in the story. Then click "Show Answer" to check your work.

Question 1: Problem 1 — What Kind of Problem Is This?

Read this story: "Tina has 7 toy cars. She gives 3 to her brother." Is this an adding to, taking from, putting together, or taking apart problem?

Show answer

This is a taking from problem! Tina starts with 7 cars and some go away (she gives 3 to her brother). Things are leaving, so it is "taking from." You would subtract: 7 − 3 = 4. Tina has 4 cars left. Great job if you got it!

Question 2: Problem 2 — Solve It!

Ben has 9 crayons. His teacher gives him 4 more. How many crayons does Ben have now?

Show answer

This is an "adding to" problem. Ben gets more crayons! 9 + 4 = 13. Ben has 13 crayons now. You can count up from 9: 10, 11, 12, 13. Nice work! 🎨

Question 3: Problem 3 — A Bit Harder!

There are 8 birds in a tree. Then 5 birds fly away. How many birds are still in the tree?

Show answer

Birds are flying away — things are leaving! This is a "taking from" problem. We subtract. 8 − 5 = 3. There are 3 birds still in the tree. You can count back from 8: 7, 6, 5, 4, 3. Awesome! 🐦

Question 4: Problem 4 — Real Life!

You have 6 red apples and 9 green apples in a basket. How many apples do you have altogether?

Show answer

We have two groups of apples and we want to know the total. The word "altogether" is a clue! This is a "putting together" problem. We add. 6 + 9 = 15. You have 15 apples altogether. Yum! You can draw 6 circles and 9 circles and count them all. 🍎🍏

Question 5: Problem 5 — Think Hard!

There are 14 kids on the playground. 8 of them are playing tag. The rest are on the swings. How many kids are on the swings?

Show answer

This is a "taking apart" problem! We know the total (14 kids) and one part (8 playing tag). We need to find the other part (kids on swings). 14 − 8 = 6. There are 6 kids on the swings! Think of it this way: 14 is the whole group. 8 is one part. To find the missing part, we subtract. You are a math superstar! ⭐

Summary

What We Learned Today

Summary

Today you learned how to solve word problems using addition and subtraction with numbers up to 20. There are four kinds of word problems. Adding to means you start with some and get more. Taking from means you start with some and lose some. Putting together means you combine two groups to find the total. Taking apart means you know the total and need to find a missing part.

To solve any word problem, follow three steps: read the story, decide if you add or subtract, and write the number sentence and solve. Look for clue words like "in all," "left," "altogether," and "how many more." You can use pictures, fingers, or a number line to help you. You are building skills that will help you with math for the rest of your life. Keep up the great work! 🌟