Word Problems
Learn
Word problems help us use math in real life! In this lesson, you will learn how to read a problem carefully, decide whether to add or subtract, and find the answer.
The 4-Step Problem Solving Process
- Read the problem carefully. Read it twice!
- Understand what the problem is asking. What do you need to find?
- Plan your solution. Will you add or subtract? Write a number sentence.
- Solve and check your answer. Does it make sense?
Key Words to Look For
Addition Words
- in all
- altogether
- total
- combined
- sum
- more than
- increased by
Subtraction Words
- left
- remaining
- difference
- fewer than
- less than
- how many more
- decreased by
Examples
Example 1: Addition Word Problem
Problem: A school library has 458 fiction books and 327 non-fiction books. How many books does the library have in all?
Key words: "in all" tells us to add
Number sentence: 458 + 327 = ?
Solution: 458 + 327 = 785
Answer: The library has 785 books in all.
Example 2: Subtraction Word Problem
Problem: Maria saved 542 stickers. She gave 178 stickers to her friends. How many stickers does Maria have left?
Key words: "left" tells us to subtract
Number sentence: 542 - 178 = ?
Solution: 542 - 178 = 364
Answer: Maria has 364 stickers left.
Example 3: Comparison Word Problem
Problem: Oak Elementary has 623 students. Pine Elementary has 485 students. How many more students does Oak Elementary have?
Key words: "how many more" tells us to subtract
Number sentence: 623 - 485 = ?
Solution: 623 - 485 = 138
Answer: Oak Elementary has 138 more students.
Practice
Solve each word problem. Show your work and write a complete answer sentence.
1. A bakery made 234 cupcakes in the morning and 189 cupcakes in the afternoon. How many cupcakes did they make altogether?
2. A toy store had 650 toys. They sold 283 toys during a sale. How many toys are left?
3. There are 412 red apples and 358 green apples in a warehouse. What is the total number of apples?
4. A farmer has 500 chickens. If 247 chickens are in the barn, how many chickens are outside?
5. The zoo had 387 visitors on Saturday and 429 visitors on Sunday. How many visitors came to the zoo that weekend?
6. Emma read 156 pages of her book last week. This week she read 198 pages. How many pages has she read in all?
7. A school needs 800 pencils for the year. They already have 356 pencils. How many more pencils do they need?
8. Town A has 725 houses. Town B has 589 houses. How many more houses does Town A have than Town B?
9. A movie theater has 450 seats. If 287 seats are filled, how many seats are empty?
10. Marcus collected 268 baseball cards. His sister gave him 175 more cards. How many cards does Marcus have now?
Check Your Understanding
Question 1: What are the four steps in the problem-solving process?
Answer: Read, Understand, Plan, Solve
Question 2: If a problem asks "how many are left," should you add or subtract?
Answer: Subtract
Question 3: What key words tell you to add?
Answer: "in all," "altogether," "total," "combined," "sum," "more than"
Question 4: Why is it important to write a complete answer sentence?
Answer: It helps you check that your answer makes sense and fully answers the question.
Next Steps
- Practice writing your own word problems for a partner to solve
- Look for addition and subtraction situations in your daily life
- Move on to Common Mistakes to learn what errors to avoid