🎯 First Grade Addition Strategies - Complete Guide

🔢 1. Add Doubles

Doubles Strategy: Adding the same number to itself!

n + n = 2n

(Same Number + Same Number)

Doubles Facts (0-10):

0 + 0 = 0
1 + 1 = 2
2 + 2 = 4
3 + 3 = 6
4 + 4 = 8
5 + 5 = 10
6 + 6 = 12
7 + 7 = 14
8 + 8 = 16
9 + 9 = 18
10 + 10 = 20

💡 Memory Trick: Doubles are EASY! Just count by 2s: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20!

Visual Pattern:
🍎🍎 → 1 + 1 = 2
🍊🍊🍊🍊 → 2 + 2 = 4
🍇🍇🍇🍇🍇🍇 → 3 + 3 = 6

➕ 2. Add Using Doubles Plus One (Near Doubles)

Doubles Plus One: If you know doubles, just add ONE more!

n + (n + 1) = (n + n) + 1

Example: 5 + 6 = (5 + 5) + 1 = 10 + 1 = 11

Doubles Plus One Facts:

1 + 2 = (1 + 1) + 1 = 2 + 1 = 3
2 + 3 = (2 + 2) + 1 = 4 + 1 = 5
3 + 4 = (3 + 3) + 1 = 6 + 1 = 7
4 + 5 = (4 + 4) + 1 = 8 + 1 = 9
5 + 6 = (5 + 5) + 1 = 10 + 1 = 11
6 + 7 = (6 + 6) + 1 = 12 + 1 = 13
7 + 8 = (7 + 7) + 1 = 14 + 1 = 15
8 + 9 = (8 + 8) + 1 = 16 + 1 = 17
9 + 10 = (9 + 9) + 1 = 18 + 1 = 19

Steps to Use Doubles Plus One:

Find the double of the smaller number
Add 1 more to that double
You have your answer!

➖ 3. Add Using Doubles Minus One

Doubles Minus One: Use doubles, then subtract ONE!

n + (n - 1) = (n + n) - 1

Example: 7 + 6 = (7 + 7) - 1 = 14 - 1 = 13

Doubles Minus One Facts:

2 + 1 = (2 + 2) - 1 = 4 - 1 = 3
3 + 2 = (3 + 3) - 1 = 6 - 1 = 5
4 + 3 = (4 + 4) - 1 = 8 - 1 = 7
5 + 4 = (5 + 5) - 1 = 10 - 1 = 9
6 + 5 = (6 + 6) - 1 = 12 - 1 = 11
7 + 6 = (7 + 7) - 1 = 14 - 1 = 13
8 + 7 = (8 + 8) - 1 = 16 - 1 = 15
9 + 8 = (9 + 9) - 1 = 18 - 1 = 17
10 + 9 = (10 + 10) - 1 = 20 - 1 = 19

💡 When to Use: Use doubles minus one when the larger number has an easy double!
Example: For 6 + 5, think: 6 + 6 = 12, then take away 1 = 11

🎲 4. Add Three Numbers - Use Doubles

Strategy: Look for doubles first, then add the third number!

a + b + c → Find doubles first!

If a = b, then: (a + a) + c

Examples with Doubles:

3 + 3 + 2 = (3 + 3) + 2 = 6 + 2 = 8
5 + 4 + 5 = (5 + 5) + 4 = 10 + 4 = 14
2 + 6 + 2 = (2 + 2) + 6 = 4 + 6 = 10
4 + 4 + 7 = (4 + 4) + 7 = 8 + 7 = 15
6 + 3 + 6 = (6 + 6) + 3 = 12 + 3 = 15

Steps:

Circle or mark the two numbers that are the same (doubles)
Add those doubles first
Then add the third number to your double

Visual Example: 4 + 3 + 4
Step 1: Circle the 4s → (4 + 4) + 3
Step 2: Add doubles → 8 + 3
Step 3: Add the last number → 11

🔟 5. Complete the Addition Sentence - Make Ten

Make Ten Strategy: Break apart numbers to make 10 first!

a + b = (a + c) + (b - c) where (a + c) = 10

Example: 8 + 5 = (8 + 2) + (5 - 2) = 10 + 3 = 13

Make Ten Examples:

7 + 5 = (7 + 3) + 2 = 10 + 2 = 12
8 + 4 = (8 + 2) + 2 = 10 + 2 = 12
9 + 3 = (9 + 1) + 2 = 10 + 2 = 12
9 + 6 = (9 + 1) + 5 = 10 + 5 = 15
8 + 7 = (8 + 2) + 5 = 10 + 5 = 15
6 + 6 = (6 + 4) + 2 = 10 + 2 = 12

💡 Friends of Ten (Number Bonds to 10):

1 + 9 = 10 | 2 + 8 = 10 | 3 + 7 = 10
4 + 6 = 10 | 5 + 5 = 10

Memorize these pairs to use Make Ten strategy faster!

Step-by-Step: 7 + 5 = ?
Step 1: How much does 7 need to make 10? → 3
Step 2: Break 5 into 3 + 2 → 7 + (3 + 2)
Step 3: Add 7 + 3 = 10
Step 4: Add 10 + 2 = 12
Answer: 12

➕➕➕ 6. Add Three Numbers - Make Ten

Strategy: Look for two numbers that add up to 10, then add the third!

a + b + c → Find which two = 10!

If a + b = 10, then: 10 + c

Examples Making Ten:

4 + 3 + 6 = (4 + 6) + 3 = 10 + 3 = 13
7 + 2 + 3 = (7 + 3) + 2 = 10 + 2 = 12
5 + 5 + 4 = (5 + 5) + 4 = 10 + 4 = 14
8 + 2 + 5 = (8 + 2) + 5 = 10 + 5 = 15
1 + 6 + 9 = (1 + 9) + 6 = 10 + 6 = 16
3 + 7 + 4 = (3 + 7) + 4 = 10 + 4 = 14

Steps:

Look at all three numbers
Find TWO numbers that make 10
Circle or connect those two numbers
Add them to make 10
Add the third number to 10

Example: 6 + 8 + 4 = ?
Which two make 10? → 6 + 4 = 10
Rewrite: (6 + 4) + 8 = 10 + 8 = 18
Answer: 18

🔢🔟 7. Add Two Multiples of Ten

Multiples of Ten: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

10a + 10b = 10(a + b)

Just add the tens digit, then write a 0!

Adding Multiples of Ten:

10 + 10 = 20 (1 + 1 = 2 → 20)
10 + 20 = 30 (1 + 2 = 3 → 30)
20 + 20 = 40 (2 + 2 = 4 → 40)
20 + 30 = 50 (2 + 3 = 5 → 50)
30 + 30 = 60 (3 + 3 = 6 → 60)
30 + 40 = 70 (3 + 4 = 7 → 70)
40 + 50 = 90 (4 + 5 = 9 → 90)
50 + 50 = 100 (5 + 5 = 10 → 100)

💡 Super Easy Trick:

Ignore the zeros
Add the tens digits (the first number)
Put a zero at the end

Example: 40 + 30 → Think 4 + 3 = 7 → Write 70!

➕🔟 8. Add a Multiple of Ten

Strategy: Adding 10, 20, 30, etc. to any number

a + 10b = (a ÷ 10 + b) × 10 + (a mod 10)

Simpler: Just add to the tens place!

Adding 10:

5 + 10 = 15
12 + 10 = 22
23 + 10 = 33
34 + 10 = 44
45 + 10 = 55

Pattern: The ones digit stays the same, tens digit goes up by 1!

Adding 20:

7 + 20 = 27
13 + 20 = 33
25 + 20 = 45
34 + 20 = 54
42 + 20 = 62

Pattern: The ones digit stays the same, tens digit goes up by 2!

Adding 30:

8 + 30 = 38
15 + 30 = 45
22 + 30 = 52
31 + 30 = 61

Quick Method:

Keep the ones digit the same
Add the multiple of ten to the tens place
Example: 17 + 30 → 1 + 3 = 4 (tens) → 47

🎯 9. Add Three Numbers (General Strategy)

Associative Property: You can add numbers in any order!

(a + b) + c = a + (b + c)

Group the easiest pair first!

What to Look For:

Two numbers that make 10
Two numbers that are doubles
Two small numbers that are easy to add
A multiple of 10 and another number

Different Strategies for Different Problems:

Make 10: 7 + 5 + 3 = (7 + 3) + 5 = 10 + 5 = 15
Doubles: 4 + 6 + 4 = (4 + 4) + 6 = 8 + 6 = 14
Easy Pair: 2 + 8 + 3 = 2 + (8 + 3) = 2 + 11 = 13
Multiple of 10: 10 + 5 + 3 = 10 + (5 + 3) = 10 + 8 = 18

More Practice Examples:

6 + 7 + 4 = (6 + 4) + 7 = 10 + 7 = 17
5 + 3 + 5 = (5 + 5) + 3 = 10 + 3 = 13
8 + 2 + 9 = (8 + 2) + 9 = 10 + 9 = 19
3 + 3 + 8 = (3 + 3) + 8 = 6 + 8 = 14
9 + 1 + 7 = (9 + 1) + 7 = 10 + 7 = 17

Decision Tree for Adding 3 Numbers:
1. Do any two make 10? → Use Make Ten
2. Are any two the same? → Use Doubles
3. Is one number 10 or a multiple of 10? → Add that last
4. Pick the two easiest numbers to add first!

📖 10. Add Three Numbers - Word Problems

Strategy: Read carefully, find the three numbers, choose the best strategy!

Example 1 (Make Ten):
Sarah has 7 apples. Tom gives her 3 apples. Then Mary gives her 4 more apples. How many apples does Sarah have now?

Numbers: 7 + 3 + 4
Strategy: Make Ten (7 + 3 = 10)
Solution: (7 + 3) + 4 = 10 + 4 = 14 apples

Example 2 (Doubles):
There are 5 red balloons, 5 blue balloons, and 6 yellow balloons. How many balloons in all?

Numbers: 5 + 5 + 6
Strategy: Doubles (5 + 5 = 10)
Solution: (5 + 5) + 6 = 10 + 6 = 16 balloons

Example 3 (Multiple of Ten):
Jake has 10 toy cars. He gets 4 more for his birthday and 3 more from his friend. How many toy cars does Jake have?

Numbers: 10 + 4 + 3
Strategy: Add to 10 first
Solution: 10 + (4 + 3) = 10 + 7 = 17 toy cars

Example 4 (Easy Pair):
Emma sees 2 birds on a tree. Then 2 more birds land. Finally, 8 more birds arrive. How many birds are on the tree?

Numbers: 2 + 2 + 8
Strategy: Doubles first (2 + 2 = 4)
Solution: (2 + 2) + 8 = 4 + 8 = 12 birds

Steps to Solve Word Problems:

Read the problem carefully
Underline or circle the three numbers
Write the addition sentence: ___ + ___ + ___ = ?
Choose your strategy (make ten, doubles, easy pair)
Solve step by step
Write your answer with the label (apples, toys, etc.)

📊 Quick Strategy Reference Chart

When to Use Each Strategy:

🔢 Doubles: When adding the same number (3 + 3, 7 + 7)
➕ Doubles ± 1: When numbers are close (6 + 7, 8 + 7)
🔟 Make Ten: When one number is close to 10 (8 + 5, 9 + 4)
🎯 Three Numbers: Look for tens, doubles, or easy pairs
🔢🔟 Multiples of 10: Adding 10, 20, 30, 40, 50...

Remember: There's no single "right" strategy! Use the one that makes the problem easiest for YOU! 🌟