Solved Exercises on One Step Word Problems with Addition and Subtraction in Grade 3

Master one step word problems with addition and subtraction: finding totals, differences, and solving real-world scenarios through these 10 detailed exercises.

Solution: Exercises 1 to 3
1 Addition problem
Exercise 1
Sarah has 12 stickers. Her friend gives her 7 more stickers. How many stickers does Sarah have now?
Definition:

Addition word problem: Finding the total when combining two or more quantities

Solution method:
  1. Identify the numbers involved: 12 and 7
  2. Recognize the operation needed: addition (combining quantities)
  3. Add the numbers together
Starting amount
12 stickers
Added amount
+ 7 stickers
Total
19 stickers
Step 1: Identify what we know

Sarah starts with 12 stickers

Her friend gives her 7 more stickers

Step 2: Determine the operation

Keywords: "more", "now" indicate addition

Step 3: Perform the calculation

12 + 7 = 19

Step 4: State the answer in context

Sarah has 19 stickers now

12 + 7 = 19 stickers
Final answer:

Sarah has 19 stickers now

Applied rules:

• Keyword identification: Look for words indicating addition

• Operation selection: Choose addition for combining quantities

• Calculation: Add the numbers together

2 Subtraction problem
Exercise 2
Tom had 25 marbles. He gave 9 marbles to his sister. How many marbles does Tom have left?
Definition:

Subtraction word problem: Finding what remains after taking away a quantity

Starting amount
25 marbles
Amount taken away
- 9 marbles
Remaining
16 marbles
Step 1: Identify what we know

Tom started with 25 marbles

He gave away 9 marbles

Step 2: Determine the operation

Keywords: "gave", "left" indicate subtraction

Step 3: Perform the calculation

25 - 9 = 16

Step 4: State the answer in context

Tom has 16 marbles left

25 - 9 = 16 marbles
Final answer:

Tom has 16 marbles left

Applied rules:

• Keyword identification: Look for words indicating subtraction

• Operation selection: Choose subtraction for taking away

• Calculation: Subtract the smaller number from the larger

3 Addition problem
Exercise 3
There are 14 red apples and 8 green apples in a basket. How many apples are there in total?
Definition:

Addition word problem: Finding the total when combining different groups

Red apples
14 apples
Green apples
+ 8 apples
Total
22 apples
Step 1: Identify what we know

There are 14 red apples

There are 8 green apples

Step 2: Determine the operation

Keywords: "total" indicates addition

Step 3: Perform the calculation

14 + 8 = 22

Step 4: State the answer in context

There are 22 apples in total

14 + 8 = 22 apples
Final answer:

There are 22 apples in total

Applied rules:

• Keyword identification: Look for words indicating addition

• Operation selection: Choose addition for combining groups

• Calculation: Add the numbers together

Solution: Exercises 4 to 5
4 Subtraction problem
Exercise 4
Emma collected 32 seashells at the beach. She gave 15 seashells to her friend. How many seashells does Emma have now?
Definition:

Subtraction word problem: Finding what remains after giving away part of a collection

Starting amount
32 seashells
Given away
- 15 seashells
Remaining
17 seashells
Step 1: Identify what we know

Emma started with 32 seashells

She gave away 15 seashells

Step 2: Determine the operation

Keywords: "gave", "now" indicate subtraction

Step 3: Perform the calculation

32 - 15 = 17

Step 4: State the answer in context

Emma has 17 seashells now

32 - 15 = 17 seashells
Final answer:

Emma has 17 seashells now

Applied rules:

• Keyword identification: Look for words indicating subtraction

• Operation selection: Choose subtraction for giving away

• Calculation: Subtract the given amount from the total

5 Addition problem
Exercise 5
On Monday, Jake read 18 pages of his book. On Tuesday, he read 14 more pages. How many pages did Jake read in total?
Definition:

Addition word problem: Finding the total when combining amounts over time

Monday
18 pages
Tuesday
+ 14 pages
Total
32 pages
Step 1: Identify what we know

Jake read 18 pages on Monday

He read 14 pages on Tuesday

Step 2: Determine the operation

Keywords: "total" indicates addition

Step 3: Perform the calculation

18 + 14 = 32

Step 4: State the answer in context

Jake read 32 pages in total

18 + 14 = 32 pages
Final answer:

Jake read 32 pages in total

Applied rules:

• Keyword identification: Look for words indicating addition

• Operation selection: Choose addition for combining amounts

• Calculation: Add the numbers together

Addition and Subtraction Rules
Addition: A + B = C
Combining Quantities
Subtraction: A - B = C
Taking Away or Finding Difference
+
Addition
more, total, altogether, sum, increase, combine
-
Subtraction
less, fewer, left, difference, decrease, take away
1
Read the problem carefully
2
Identify key numbers and information
3
Find keywords that suggest the operation
4
Set up the equation
5
Solve and check your answer
Key Concept: Operation Keywords

Learning to recognize keywords helps determine which operation to use in word problems.

Common Problem Types
  • Addition: combining, total, altogether
  • Subtraction: taking away, difference, remaining
🍎
Addition: More apples
🍊
Subtraction: Fewer oranges
Complete Guide to Addition and Subtraction Word Problems
Read → Think → Solve → Check
Problem Solving Process
Key definitions:

Word problem: A mathematical question presented in narrative form

One-step problem: A problem requiring only one mathematical operation to solve

Keywords: Words that indicate which mathematical operation to use

Complete methodology:
  1. Read carefully: Understand the situation described
  2. Identify information: Find numbers and important details
  3. Look for keywords: Determine the required operation
  4. Set up equation: Write the mathematical expression
  5. Solve: Calculate the answer
  6. Check: Verify the answer makes sense
Tip 1: Draw pictures or use manipulatives to visualize the problem.
Tip 2: Underline or circle important numbers and keywords.
Tip 3: Always write your answer in a complete sentence.
Tip 4: Estimate your answer before calculating to check reasonableness.
Common errors: Misreading the question, choosing wrong operation, calculation mistakes.
Success strategies: Practice keyword recognition, use visual aids, check work.
Key rules to remember:

• Addition: combines quantities ("more", "total", "altogether")

• Subtraction: finds difference or remaining ("less", "left", "fewer")

Addition and Subtraction Word Problems

+
Addition
more, total, altogether, sum, increase, combine
-
Subtraction
less, fewer, left, difference, decrease, take away
1
Read the entire problem
2
Circle numbers and underline keywords
3
Choose the correct operation
4
Solve and write the answer in a sentence

Questions & Answers

Question: How do I know whether to add or subtract in a word problem? Sometimes the keywords are confusing.

Answer: Focus on the action described in the problem:

  • For addition: Something is being added, combined, or increased
  • For subtraction: Something is being taken away, compared, or decreased

Examples:

  • "Sarah has 5 apples and gets 3 more" → Addition (5 + 3)
  • "Tom had 10 marbles and lost 4" → Subtraction (10 - 4)
  • "How many more apples does Sarah have than Tom?" → Subtraction (comparison)

Always think about whether the total is getting bigger (addition) or smaller (subtraction).

Question: What should I do if I'm not sure which operation to use in a word problem?

Answer: Try these strategies:

  • Draw a picture: Visualize what's happening in the problem
  • Act it out: Use objects or gestures to represent the situation
  • Think about the story: Is something being added or taken away?
  • Try both: See which answer makes more sense in the context

Remember, addition makes numbers bigger and subtraction makes them smaller.

Question: How can I check if my answer to an addition or subtraction word problem is reasonable?

Answer: There are several ways to verify your answer:

  • Estimate: Round numbers and do a quick mental calculation
  • Re-read: Check if your answer fits the story in the problem
  • Reverse operation: If you added, subtract to check; if you subtracted, add to check

For example, if you found that Sarah has 20 apples after starting with 12 and getting 8 more, check: 12 + 8 = 20 ✓

Always ask yourself: "Does this answer make sense in the context of the problem?"

Complete Summary: One Step Word Problems with Addition and Subtraction

Definitions of Key Concepts

Word Problem: A mathematical question presented in narrative form using everyday situations.

One-Step Problem: A problem that requires only one mathematical operation (addition or subtraction) to solve.

Keywords: Words that indicate which mathematical operation to use (e.g., "more" suggests addition, "left" suggests subtraction).

Operations: Addition (+) and subtraction (-) used to solve mathematical problems.

Addition: The process of combining two or more quantities to find a total.

Subtraction: The process of taking away one quantity from another to find the difference or remaining amount.

Core Rules and Principles

Addition: Used when combining quantities, finding totals, or increasing amounts. Keywords: more, total, altogether, sum, increase.

Subtraction: Used when taking away, finding differences, or determining what remains. Keywords: less, fewer, left, difference, decrease.

Problem-Solving Process: Read the problem, identify important information, determine the operation, set up the equation, solve, and check your answer.

Reasonableness Check: Always verify that your answer makes sense in the context of the problem.

Step-by-Step Method
  1. Read Carefully: Understand the situation described in the problem.
  2. Identify Information: Find numbers and important details.
  3. Look for Keywords: Determine which operation to use based on clue words.
  4. Set Up Equation: Write the mathematical expression that represents the problem.
  5. Solve: Calculate the answer using the appropriate operation.
  6. Check: Verify that your answer makes sense in the context of the problem.
Examples (Simple to Advanced)

Simple Addition: "Tom has 3 apples. He gets 2 more. How many does he have?" (3 + 2 = 5)

Simple Subtraction: "Sarah has 8 cookies. She eats 3. How many are left?" (8 - 3 = 5)

Intermediate Addition: "There are 14 red cars and 9 blue cars. How many cars total?" (14 + 9 = 23)

Intermediate Subtraction: "Jake had 27 marbles. He lost 12. How many does he have left?" (27 - 12 = 15)

Advanced Comparison: "Emma read 35 pages. Tom read 28 pages. How many more did Emma read?" (35 - 28 = 7)

Tips, Tricks, and Common Pitfalls

Tips: Draw pictures to visualize the problem; underline important numbers; circle keywords; estimate your answer first.

Tricks: Remember that "more than" often means subtraction for comparison problems; "in all" usually means addition.

Common Pitfalls: Choosing the wrong operation due to misreading keywords; forgetting to include units in your answer; not checking if the answer makes sense.

Memory Aid: "AS" - Addition, Subtraction. Think of the action: Adding or Taking away.

Checking Strategy: Always verify by performing the reverse operation.

Key Notes for Memorization

Addition Keywords: more, total, altogether, sum, combined, increased by, in all.

Subtraction Keywords: less, fewer, left, difference, decrease, take away, how many more, how many fewer.

Always Remember: Write your final answer in a complete sentence that addresses the question asked.

Visual Representation: Use drawings or manipulatives to model the problem situation.

Estimation Strategy: Round numbers to check if your answer is reasonable.