Complete Guide to Addition with Sums of 20 in Grade 1

Master addition with sums up to 20: visual counting, number bonds, and addition strategies through these 5 detailed exercises with comprehensive learning strategies.

Complete Learning Summary

What is Addition with Sums of 20?

Definition: Addition with sums of 20 involves adding numbers where the total result equals 20 or less, focusing on developing foundational addition skills up to the number 20.

  • Sum Limit: Results range from 0 to 20
  • Number Sense: Understanding quantities up to 20
  • Place Value: Introduction to tens and ones
  • Strategy Development: Building mental math skills

Core Rules and Principles

  • Commutative Property: Order doesn't matter in addition (8 + 12 = 12 + 8)
  • Identity Property: Adding zero doesn't change the number (15 + 0 = 15)
  • Associative Property: Grouping doesn't affect the sum (5 + (7 + 8) = (5 + 7) + 8)
  • Counting On: Starting with the larger number and counting up
  • Make Ten Strategy: Breaking numbers to form groups of ten

Step-by-Step Method

  1. Identify Numbers: Recognize the addends to be combined
  2. Choose Strategy: Select the most efficient method (counting, making ten, etc.)
  3. Execute Addition: Apply the chosen strategy
  4. Verify Result: Check that the sum is reasonable
  5. Record Answer: Write the final sum

Addition Strategies for Sums to 20

  • Counting All: Count all objects from beginning
  • Counting On: Start with the first number and count up
  • Make Ten: Break apart numbers to create groups of ten
  • Number Bonds: Use known fact families
  • Doubles Plus One: Use doubles facts as a foundation

Tips for Addition Success

  • Start Small: Begin with sums to 10 before moving to 20
  • Use Manipulatives: Counters, blocks, or fingers for support
  • Practice Number Bonds: Learn pairs that make 10 and 20
  • Memorize Facts: Build automaticity with basic facts
  • Check Work: Verify answers using alternative methods
  • Be Patient: Allow time for skill development

Common Addition Challenges

  • Carrying Tens: Difficulty when sums cross ten
  • Memory Overload: Struggling to hold numbers in mind
  • Strategy Selection: Choosing inefficient methods
  • Counting Errors: Mistakes in counting large numbers
  • Number Recognition: Confusion with larger numbers
Example Problems with Sums to 20
1 Basic Addition to 20
Example 1
Add: 8 + 7 = ?
Definition:

Addition: Combining two or more numbers to find their total sum

Make Ten Strategy:
  1. Break apart 7 into 2 and 5
  2. Add 8 + 2 = 10
  3. Add 10 + 5 = 15
15
8
7
Step 1: Identify the numbers

We have 8 and 7 to add

Step 2: Use make ten strategy

8 + 7 = 8 + (2 + 5) = (8 + 2) + 5 = 10 + 5 = 15

Step 3: Verify the result

Count: 8, 9, 10, 11, 12, 13, 14, 15

8 + 7 = 15
Final answer:

8 + 7 = 15

Applied rules:

• Make Ten Strategy: Break apart numbers to form tens

• Associative Property: Grouping doesn't change the sum

• Counting Verification: Double-check with counting

2 Addition Crossing Ten
Example 2
Add: 9 + 6 = ?
Definition:

Crossing Ten: Addition problems where the sum exceeds 10

15
9
6
0
5
10
15
20
Step 1: Start with 9

Begin at 9 on the number line

Step 2: Count up 6 more

9 + 1 = 10, 10 + 5 = 15

Step 3: Reach the sum

9 + 6 = 15

9 + 6 = 15
Final answer:

9 + 6 = 15

Applied rules:

• Counting On: Start with the larger number

• Crossing Ten: Understanding what happens at 10

• Number Line: Visual representation of addition

3 Doubles Plus One
Example 3
Add: 7 + 8 = ?
Definition:

Doubles Plus One: Using known doubles facts to solve nearby problems

15
7
8
Step 1: Recognize the pattern

7 + 8 is close to 7 + 7 (a double)

Step 2: Use doubles fact

7 + 7 = 14, so 7 + 8 = 14 + 1 = 15

Step 3: Apply the strategy

7 + 8 = (7 + 7) + 1 = 14 + 1 = 15

7 + 8 = 15
Final answer:

7 + 8 = 15

Applied rules:

• Doubles Plus One: Use known doubles facts

• Pattern Recognition: Identify related facts

• Addition Properties: Use known relationships

Advanced Addition Problems
4 Three Number Addition
Example 4
Add: 5 + 7 + 8 = ?
Definition:

Three Number Addition: Adding three separate numbers together

20
5
7
8
Step 1: Add first two numbers

5 + 7 = 12

Step 2: Add the result to the third

12 + 8 = 20

Step 3: Use associative property

(5 + 7) + 8 = 5 + (7 + 8) = 5 + 15 = 20

5 + 7 + 8 = 20
Final answer:

5 + 7 + 8 = 20

Applied rules:

• Associative Property: Grouping order doesn't matter

• Sequential Addition: Add two at a time

• Strategic Grouping: Choose easier combinations first

5 Maximum Sum to 20
Example 5
Add: 10 + 10 = ?
Definition:

Maximum Sum: Reaching the target number of 20

20
10
10
0
5
10
15
20
Step 1: Recognize the doubles fact

10 + 10 is a doubles fact

Step 2: Apply place value understanding

1 ten + 1 ten = 2 tens = 20

Step 3: Verify with counting

Count by tens: 10, 20

10 + 10 = 20
Final answer:

10 + 10 = 20

Applied rules:

• Doubles Fact: 10 + 10 = 20

• Place Value: Understanding tens and ones

• Maximum Sum: Reaching the target of 20

Questions & Answers

Question: My child struggles with addition problems that cross ten, like 8 + 7. How can I help them master these?

Answer: Use the "make ten" strategy:

  • Break apart the smaller number to make ten with the larger
  • For 8 + 7: take 2 from 7 to make 8 into 10
  • This gives us 10 + 5 = 15
  • Practice with manipulatives to build understanding

Visual aids and hands-on practice help children see the relationship.

Question: What are the most effective strategies for teaching addition to 20?

Answer: Focus on these key strategies:

  • Counting on from the larger number
  • Using doubles facts as anchors
  • Breaking apart numbers to make ten
  • Number bonds and fact families

Build fluency through varied practice and real-world applications.

Question: How can I help students memorize addition facts to 20 effectively?

Answer: Use spaced repetition and pattern recognition:

  • Practice facts in small, frequent sessions
  • Focus on patterns like doubles and near-doubles
  • Use games and timed challenges
  • Connect to visual representations

Meaningful practice builds automaticity better than rote memorization.