Solved Exercises on One-Step Word Problems in Grade 3

Master one-step word problems: addition, subtraction, multiplication, division, and mixed operations with visual representations through these 5 detailed exercises.

Solution: Exercises 1 to 3
1 Addition word problem
Exercise 1
Sarah has 15 stickers. Her friend gives her 8 more stickers. How many stickers does Sarah have now?
Definition:

One-step word problem: A problem that requires only one mathematical operation to solve. Addition: Combining two or more quantities to find a total. Look for words like "more," "total," "altogether," "combined," or "in all."

Addition method:
  1. Identify the numbers to add
  2. Recognize clue words indicating addition
  3. Write the addition sentence
  4. Solve the addition
  5. Write the answer with units
Initial stickers
15
Added stickers
8
Total
15 + 8 = 23
Step 1: Identify the numbers

Sarah has 15 stickers, gets 8 more

Step 2: Find clue words

"more" indicates addition is needed

Step 3: Write the equation

15 + 8 = ?

Step 4: Solve

15 + 8 = 23

Step 5: State the answer

Sarah has 23 stickers

Sarah has 23 stickers
Final answer:

Sarah has 23 stickers altogether

Applied rules:

• Clue words: "more" signals addition

• One operation: Only addition is needed to solve

• Verification: 15 + 8 = 23 ✓

2 Subtraction word problem
Exercise 2
Tom had 24 marbles. He lost 9 marbles while playing. How many marbles does Tom have left?
Definition:

Subtraction: Taking away a quantity from another to find what remains. Look for words like "left," "remaining," "lost," "took away," "difference," or "how many more."

Initial marbles
24
Marbles lost
9
Remaining
24 - 9 = 15
Step 1: Identify the numbers

Tom started with 24 marbles, lost 9

Step 2: Find clue words

"lost" and "left" indicate subtraction is needed

Step 3: Write the equation

24 - 9 = ?

Step 4: Solve

24 - 9 = 15

Step 5: State the answer

Tom has 15 marbles left

Tom has 15 marbles left
Final answer:

Tom has 15 marbles remaining

Applied rules:

• Clue words: "lost" and "left" signal subtraction

• One operation: Only subtraction is needed to solve

• Verification: 15 + 9 = 24 ✓

3 Multiplication word problem
Exercise 3
There are 4 rows of chairs in the classroom. Each row has 6 chairs. How many chairs are there in total?
Definition:

Multiplication: Repeated addition of equal groups. Look for words like "each," "every," "times," "groups of," "rows of," or "sets of." This represents equal groups being counted together.

Number of rows
4
Chairs per row
6
Total chairs
4 × 6 = 24
Step 1: Identify the groups and items

4 rows with 6 chairs in each row

Step 2: Find clue words

"each row has" indicates equal groups, signaling multiplication

Step 3: Write the equation

4 groups of 6 = 4 × 6 = ?

Step 4: Solve

4 × 6 = 24

Step 5: State the answer

There are 24 chairs in total

There are 24 chairs
Final answer:

There are 24 chairs in total

Applied rules:

• Clue words: "each" signals multiplication

• Equal groups: Same number in each group

• Verification: 6 + 6 + 6 + 6 = 24 ✓

Rules and methods, laws,...
Operation = Clue Words + Numbers
Problem Solving
Addition Clues
More, Total, Altogether
Addition keywords
Subtraction Clues
Left, Remaining, Lost
Subtraction keywords
Multiplication Clues
Each, Per, Times
Multiplication keywords
Key definitions:

One-step word problem: A problem that requires only one mathematical operation (addition, subtraction, multiplication, or division) to solve.

Clue words: Words in the problem that indicate which mathematical operation to use.

Addition: Combining amounts to find a total (more, total, altogether, sum).

Subtraction: Finding what remains after taking away (left, remaining, spent, difference).

Multiplication: Finding total of equal groups (each, per, times, groups of).

Division: Sharing equally or finding how many groups (each, per, shared, divided).

Problem-solving methodology:
  1. Read carefully: Understand the full problem
  2. Identify numbers: Find all the numbers mentioned
  3. Find clue words: Determine which operation to use
  4. Set up equation: Write the mathematical expression
  5. Solve: Perform the calculation
  6. Check: Verify your answer makes sense
Tip 1: Look for clue words to determine the operation needed.
Tip 2: Draw pictures or diagrams to visualize the problem.
Tip 3: Always include the correct units in your answer.
Tip 4: Check if your answer is reasonable in the context of the problem.
Common errors: Misreading clue words, choosing wrong operation, calculation mistakes, forgetting units, not checking if answer makes sense.
Real-world applications: Shopping (finding totals), cooking (measuring ingredients), organizing items, sharing resources, calculating time.
Problem-solving rules:

• Addition: More, total, altogether, combined, in all

• Subtraction: Left, remaining, difference, lost, spent

• Multiplication: Each, per, times, groups of, rows of

• Division: Shared equally, divided among, per, each

• Always verify your answer makes sense in context

Solution: Exercises 4 to 5
4 Division word problem
Exercise 4
Mrs. Johnson has 20 pencils to share equally among 4 students. How many pencils does each student get?
Definition:

Division: Splitting a total amount into equal parts. Look for words like "share equally," "divide among," "each," "per," or "split into groups."

Total pencils
20
Number of students
4
Pencils per student
20 ÷ 4 = 5
Step 1: Identify the total and number of groups

20 pencils to be shared among 4 students

Step 2: Find clue words

"share equally" indicates division is needed

Step 3: Write the equation

20 ÷ 4 = ?

Step 4: Solve

20 ÷ 4 = 5

Step 5: State the answer

Each student gets 5 pencils

Step 6: Verify

5 × 4 = 20 ✓

Each student gets 5 pencils
Final answer:

Each student gets 5 pencils

Applied rules:

• Clue words: "share equally" signals division

• Equal sharing: Same amount for each person

• Verification: Multiply back to check: 5 × 4 = 20

5 Mixed operation word problem
Exercise 5
A farmer has 36 apples. He puts 4 apples in each basket. How many baskets does he need?
Definition:

Grouping problem: A type of division problem where you find how many equal groups can be made from a total amount. This involves distributing items into sets of equal size.

Total apples
36
Apples per basket
4
Number of baskets
36 ÷ 4 = 9
Step 1: Identify the total and group size

36 apples total, 4 apples per basket

Step 2: Find clue words

"puts 4 apples in each basket" means grouping, which requires division

Step 3: Write the equation

36 ÷ 4 = ?

Step 4: Solve

36 ÷ 4 = 9

Step 5: State the answer

The farmer needs 9 baskets

Step 6: Verify

9 × 4 = 36 ✓

The farmer needs 9 baskets
Final answer:

The farmer needs 9 baskets

Applied rules:

• Grouping: Division to find number of equal groups

• Context: Items distributed into sets of equal size

• Verification: Multiply back to check: 9 × 4 = 36

Complete Summary: One-Step Word Problems
Operation = Clue Words + Numbers
Problem Solving
Key definitions:

One-step word problem: A mathematical problem expressed in words that requires only one arithmetic operation (addition, subtraction, multiplication, or division) to solve.

Clue words: Specific words in the problem that indicate which mathematical operation should be used to solve the problem.

Addition: Combining two or more quantities to find a total amount. Words include: more, total, altogether, combined, in all, sum.

Subtraction: Finding the difference between two quantities or what remains after taking away. Words include: left, remaining, difference, lost, spent, how many more.

Multiplication: Finding the total when equal groups are combined. Words include: each, per, times, groups of, rows of, sets of.

Division: Splitting a total into equal parts or finding how many equal groups can be made. Words include: share equally, divided among, per, each, split.

Complete problem-solving methodology:
  1. Read carefully: Read the entire problem to understand the situation
  2. Identify numbers: Circle or underline all the numbers mentioned
  3. Find clue words: Look for words that indicate the operation needed
  4. Visualize: Draw a picture or diagram if it helps
  5. Set up equation: Write the mathematical expression
  6. Solve: Perform the calculation carefully
  7. Check: Verify the answer makes sense in the context
Tip 1: Look for clue words to determine the operation needed, but always consider the full context.
Tip 2: Draw pictures or use objects to represent the problem when you're stuck.
Tip 3: Always include the correct units (apples, dollars, people, etc.) in your answer.
Tip 4: Check if your answer is reasonable by estimating or working backwards.
Tip 5: Remember that one-step problems require only one operation, not multiple steps.
Common errors: Misreading clue words, choosing the wrong operation, making calculation mistakes, forgetting to include units, not checking if the answer makes sense in the problem's context.
Real-world applications: Shopping (finding totals and change), cooking (measuring ingredients), organizing items (counting and grouping), sharing resources, calculating time and distance, budgeting.
Key problem-solving rules:

• Addition clues: more, total, altogether, combined, in all, sum, increased by

• Subtraction clues: left, remaining, difference, lost, spent, how many more, decreased by

• Multiplication clues: each, per, times, groups of, rows of, sets of, product

• Division clues: share equally, divided among, per, each, split, quotient

• Always verify your answer makes sense in the problem's context

• One-step problems require only one operation to solve

• Draw diagrams or use manipulatives to visualize the problem

Visual Guide to One-Step Word Problems

🔢
Addition Problems

Clue words: more, total, altogether

Example: 15 + 8 = 23

Combining amounts

Result is larger than parts

Subtraction Problems

Clue words: left, remaining, difference

Example: 24 - 9 = 15

Taking away

Result is smaller than original

Multiplication Problems

Clue words: each, per, times

Example: 4 × 6 = 24

Equal groups combined

Repeated addition

Division Problems

Clue words: share, each, divide

Example: 20 ÷ 4 = 5

Splitting into equal parts

Finding group size or number

Questions & Answers

Question: How can I tell if a word problem needs addition, subtraction, multiplication, or division? The words sometimes confuse me.

Answer: Look for these specific clue words in the problem:

  • Addition (+): "more," "total," "altogether," "sum," "combined," "in all," "plus," "added to"
  • Subtraction (-): "left," "remaining," "difference," "less," "take away," "spent," "lost," "decreased by"
  • Multiplication (×): "each," "per," "times," "groups of," "rows of," "sets of," "product of"
  • Division (÷): "shared equally," "divided among," "per," "each," "split," "quotient of"

Example: "Sarah has 15 stickers, gets 8 more" → "more" means addition

Example: "Tom had 24 marbles, lost 9" → "lost" means subtraction

Example: "4 rows with 6 chairs each" → "each" means multiplication

Example: "20 pencils shared among 4 students" → "shared" means division

Question: Sometimes I pick the wrong operation even when I see the clue words. What else can I do to make sure I choose the right one?

Answer: Beyond clue words, try these strategies:

  • Draw a picture: Visualize the situation described in the problem
  • Act it out: Use objects or your fingers to represent the problem
  • Think logically: Does your answer make sense? If you're sharing items, the answer should be smaller.
  • Estimate: Make a rough guess first, then see if your answer is close

Example: "4 students share 20 pencils" - draw 4 circles and distribute 20 dots. You can see each gets 5.

If you mistakenly added (4 + 20 = 24), you'd realize that doesn't make sense for sharing.

Always ask: "Does my answer make sense in the story?"

Question: I sometimes see problems that seem like they need two steps, but you said these are one-step problems. How do I know?

Answer: One-step problems require only ONE mathematical operation to solve, even if the wording seems complex:

  • One-step: Requires only addition OR subtraction OR multiplication OR division
  • Multi-step: Requires TWO or MORE operations (like add first, then subtract)

Example of one-step: "36 apples put in baskets of 4" → 36 ÷ 4 = 9 (only division needed)

Example of multi-step: "Sarah has $10, spends $3, then gets $5 more" → $10 - $3 + $5 = $12 (two operations needed)

In one-step problems, there's only one action happening: combining, taking away, grouping, or sharing.

Look for the main action in the problem - that tells you which operation to use!