Worksheets on Addition Facts Within 20 in Grade 2

Master addition facts within 20: number bonds, counting strategies, and mental math techniques through these 5 detailed worksheets.

Worksheet Solutions: Problems 1 to 3
1 Basic addition facts
Problem 1
Complete the addition: 5 + 8 = ?
Definition:

Addition: Combining two or more numbers to find their total

Sum: The answer when you add numbers together

Addition facts within 20: Addition problems where the sum is 20 or less

Making 10 strategy:
  1. Start with the larger number (8)
  2. See how many more are needed to make 10 (2 more)
  3. Take that amount from the second number (5 = 2 + 3)
  4. Add to 10: 10 + 3 = 13
Expression
5 + 8
Strategy
Make 10
Answer
13
Step 1: Identify the numbers

We have 5 and 8

Step 2: Use the "make 10" strategy

8 needs 2 more to make 10

Take 2 from 5: 5 = 2 + 3

Step 3: Add to 10

8 + 2 = 10

Then add the remaining 3: 10 + 3 = 13

5 + 8 = 13
Final answer:

5 + 8 = 13

Applied rules:

• Making 10 strategy: Break one number to make 10 first

• Decomposition: Breaking numbers into parts to make addition easier

• Verification: Always check by counting or using another method

2 Number bonds
Problem 2
Complete the addition: 11 + 7 = ?
Definition:

Number bond: Two numbers that add up to make a specific total

Part-whole relationship: Smaller parts combine to make the whole

Expression
11 + 7
Strategy
Counting on
Answer
18
Step 1: Start with the larger number

We start with 11

Step 2: Count up by the second number

Count 7 more: 12, 13, 14, 15, 16, 17, 18

Step 3: Verify the answer

We counted 7 numbers from 11: 12, 13, 14, 15, 16, 17, 18

11 + 7 = 18
Final answer:

11 + 7 = 18

Applied rules:

• Counting on: Start with the larger number and count up

• Part-whole thinking: Understanding how parts combine

• Verification: Always check by counting to confirm the answer

3 Doubles plus one
Problem 3
Complete the addition: 6 + 7 = ?
Definition:

Doubles plus one: Adding consecutive numbers (like 6 + 7)

Relationship to doubles: 6 + 7 is the same as 6 + 6 + 1

Expression
6 + 7
Strategy
Doubles plus 1
Answer
13
Step 1: Recognize the relationship

6 + 7 is the same as 6 + 6 + 1

Step 2: Use the doubles fact

6 + 6 = 12

Step 3: Add 1

12 + 1 = 13

Step 4: Confirm the answer

6 + 7 = 13

6 + 7 = 13
Final answer:

6 + 7 = 13

Applied rules:

• Doubles plus/minus strategy: Use known doubles facts

• Relationship between consecutive numbers: n + (n+1) = n + n + 1

• Mental math: Building on known facts to solve new problems

Addition Facts Within 20 Worksheets Concepts
a + b ≤ 20
Addition Facts Within 20
Doubles
5+5=10
Five plus five
Doubles
6+6=12
Six plus six
Doubles
7+7=14
Seven plus seven
Doubles
8+8=16
Eight plus eight
Doubles
9+9=18
Nine plus nine
Make 10
9+1=10
Nine and one
Make 10
8+2=10
Eight and two
Make 10
7+3=10
Seven and three
Make 10
6+4=10
Six and four
Make 10
5+5=10
Five and five
Near Doubles
6+5=11
6+5 (one less than 6+6)
Near Doubles
7+6=13
7+6 (one less than 7+7)
Near Doubles
8+7=15
8+7 (one less than 8+8)
Near Doubles
9+8=17
9+8 (one less than 9+9)
Near Doubles
5+4=9
5+4 (one less than 5+5)
Key concepts:

Addition: Combining two or more numbers to find their total

Sum: The result of adding numbers together

Addend: The numbers being added together

Number bond: A relationship showing how numbers combine to make a total

Fact family: Related addition and subtraction facts using the same numbers

Addition facts within 20: Addition problems where the sum is 20 or less

Doubles: Adding the same number twice (e.g., 6 + 6)

Near doubles: Adding consecutive numbers (e.g., 6 + 7)

Addition strategies:
  1. Counting on: Start with the larger number and count up
  2. Using doubles: Know doubles facts to solve near-doubles
  3. Make 10: Break apart numbers to make 10 first
  4. Commutative property: Change order to make it easier
  5. Visualizing: Picture objects being combined
Tip 1: Practice doubles facts daily for quick recall.
Tip 2: Use the "making 10" strategy for numbers close to 10.
Tip 3: Remember that adding 0 doesn't change the number.
Tip 4: Always verify by counting to check your answer.
Common errors: Starting to count from the first number instead of the next number, forgetting that order doesn't matter in addition.
Worksheet tip: Work systematically from top to bottom or left to right.
Addition properties:

• Commutative Property: a + b = b + a (order doesn't matter)

• Identity Property: a + 0 = a (adding zero doesn't change the number)

• Associative Property: (a + b) + c = a + (b + c) (grouping doesn't matter)

Worksheet Solutions: Problems 4 to 5
4 Mental math
Problem 4
Complete the addition: 13 + 6 = ?
Definition:

Mental math: Solving math problems in your head without writing anything down

Expression
13 + 6
Strategy
Counting on
Answer
19
Step 1: Start with 13

We begin with 13

Step 2: Count up 6 more

14, 15, 16, 17, 18, 19

Step 3: Count to verify

Start at 13, count 6 more: 14, 15, 16, 17, 18, 19

13 + 6 = 19
Final answer:

13 + 6 = 19

Applied rules:

• Counting on strategy: Start with the larger number and count up

• Addition within 20: The sum is less than or equal to 20

• Mental calculation: Use known facts to solve efficiently

5 Word problem
Problem 5
Sam has 9 marbles. His brother gives him 8 more marbles. How many marbles does Sam have now?
Definition:

Word problem: A real-world situation that can be solved using math

Problem
9 + 8 = ?
Solution
Start at 9, count 8 more
Answer
17 marbles
Step 1: Identify what we know

Sam starts with 9 marbles and gets 8 more

Step 2: Set up the equation

9 + 8 = ?

Step 3: Solve using counting

Start at 9, count 8 more: 10, 11, 12, 13, 14, 15, 16, 17

Step 4: Answer the question

Sam has 17 marbles now

9 + 8 = 17
Final answer:

Sam has 17 marbles now

Applied rules:

• Word problem solving: Identify known information and what you need to find

• Addition within 20: The sum is less than or equal to 20

• Real-world connection: Math helps us solve everyday problems

Addition Facts Within 20 Worksheets Summary
a + b ≤ 20
Addition Facts Within 20
Worksheet objectives:

Accuracy: Correctly solving addition problems within 20

Fluency: Demonstrating efficient recall of addition facts

Strategy use: Applying appropriate methods for different problems

Problem-solving: Transferring knowledge to real-world contexts

Conceptual understanding: Explaining reasoning and mathematical thinking

Worksheet completion strategies:
  1. Read carefully: Understand what each problem is asking
  2. Choose strategy: Select the most efficient method for each problem
  3. Work systematically: Go in order or group similar problems
  4. Check work: Verify answers using a different method
  5. Review: Look for patterns and common mistakes
Tip 1: Master all addition facts within 20 - they're building blocks for other math.

Tip 2: Use the "making 10" strategy for other addition problems.

Tip 3: Practice with visual aids like ten frames or number lines.

Tip 4: Always check your work by counting from the first number.

Common errors: Starting to count from the first number instead of the next number, forgetting that order doesn't matter in addition.

Worksheet tip: Use scratch paper to visualize problems if needed.

Key worksheet strategies:

Fluency: Quick and accurate recall of addition facts

Strategy selection: Choosing appropriate methods for different problems

Reasoning: Explaining the "why" behind the solution process

Application: Successfully solving word problems using addition facts

Flexibility: Using multiple approaches when one method doesn't work

Worksheet Progress Tracker
Addition Skills Practice
Progress breakdown by strategy:
Making 10: 75% accuracy
Counting on: 85% accuracy
Doubles: 90% accuracy
Near doubles: 70% accuracy

Analysis: This worksheet practice reveals areas of strength and opportunities for growth:

  • Students excel at basic counting strategies
  • Doubles facts are well mastered
  • Near doubles need additional practice
  • Strategy flexibility requires development

Worksheet Questions & Answers

Question: Why do we do addition worksheets? Is it just busy work?

Answer: Addition worksheets are far from busy work! They serve important purposes:

  • Build fluency: Practice leads to automatic recall
  • Reinforce concepts: Helps cement understanding
  • Identify patterns: Shows relationships between numbers
  • Build confidence: Success with practice builds self-esteem

Worksheets provide focused practice for important math skills!

Question: How can I help my child complete addition worksheets successfully?

Answer: Supporting worksheet success involves:

  • Create a quiet space: Minimize distractions during work time
  • Review strategies: Go over methods before starting
  • Encourage self-checking: Teach verification techniques
  • Praise effort: Acknowledge hard work, not just correct answers

Remember: consistency and encouragement go a long way!

Question: I get stuck on some problems. What should I do?

Answer: Getting stuck is normal! Try these strategies:

When you're stuck:

  • Move to the next problem and come back later
  • Try a different strategy
  • Draw a picture or use your fingers
  • Ask for help if allowed

Remember: every mathematician encounters challenges!

Question: How can I make sure my answers are correct?

Answer: Verification is an important skill:

Check your work:

  • Count from the first number again
  • Use a different strategy to solve
  • Look for patterns in your answers
  • Estimate to see if the answer makes sense

Good mathematicians always verify their solutions!

Question: What's the best way to organize my work on worksheets?

Answer: Organization helps with accuracy and efficiency:

Keep your workspace neat:

  • Work in order from top to bottom
  • Write clearly and legibly
  • Use scratch paper for calculations if needed
  • Line up numbers properly

Neat organization prevents careless errors and makes checking easier!