Grade: Grade 1 Subject: SAT/ACT Skills Unit: Mental Math Warmups SAT: Algebra ACT: Math

Quick Addition

📖 Learn

Quick addition means adding numbers fast in your head! This is called mental math. When you can add quickly, you will do better on tests and in everyday life.

What Is Quick Addition?

Quick addition is adding numbers in your head without writing them down or using your fingers. You learn to see numbers and know the answer right away!

Key Words to Know

  • Add: To put numbers together to find how many in all
  • Sum: The answer when you add numbers
  • Mental Math: Doing math in your head
  • Plus (+): The symbol that means add

Tips for Adding Fast

  • Know your doubles: 1+1=2, 2+2=4, 3+3=6, 4+4=8, 5+5=10
  • Count on: Start with the bigger number and count up
  • Make 10: Look for pairs that make 10 (like 7+3 or 6+4)
  • Plus 1 or 2: These are easy - just count one or two more!

Doubles to Remember

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

💡 Examples

See how to add numbers quickly using different strategies.

Example 1: Using Doubles

Problem: 4 + 4 = ?

Think: I know my doubles! 4 + 4 = 8

Answer: 8

Example 2: Counting On

Problem: 7 + 2 = ?

Think: Start with 7, count up 2 more: 8, 9

Answer: 9

Example 3: Making 10

Problem: 6 + 4 = ?

Think: 6 and 4 are friends that make 10!

Answer: 10

Example 4: Adding 1

Problem: 8 + 1 = ?

Think: Adding 1 means just the next number after 8.

Answer: 9

Example 5: Doubles Plus One

Problem: 5 + 6 = ?

Think: I know 5 + 5 = 10. 5 + 6 is one more, so 11!

Answer: 11

✏️ Practice

Try to solve these addition problems in your head. Time yourself to see how fast you can go!

Problem 1

3 + 3 = ?

Show Answer

6 (doubles: 3 + 3 = 6)

Problem 2

5 + 2 = ?

Show Answer

7 (count on: 5, 6, 7)

Problem 3

7 + 3 = ?

Show Answer

10 (make 10: 7 + 3 = 10)

Problem 4

9 + 1 = ?

Show Answer

10 (plus 1: the next number after 9)

Problem 5

6 + 6 = ?

Show Answer

12 (doubles: 6 + 6 = 12)

Problem 6

4 + 5 = ?

Show Answer

9 (doubles plus one: 4 + 4 = 8, plus 1 more = 9)

Problem 7

8 + 2 = ?

Show Answer

10 (make 10: 8 + 2 = 10)

Problem 8

2 + 7 = ?

Show Answer

9 (count on from 7: 8, 9)

Problem 9

5 + 5 = ?

Show Answer

10 (doubles: 5 + 5 = 10)

Problem 10

9 + 4 = ?

Show Answer

13 (count on from 9: 10, 11, 12, 13)

✅ Check Your Understanding

Answer these questions about quick addition.

Question 1

What does "mental math" mean?

Show Answer

Mental math means doing math in your head, without writing it down or using your fingers. You think about the numbers and find the answer in your mind.

Question 2

What is a "double" in math?

Show Answer

A double is when you add a number to itself. For example: 3 + 3 = 6, 4 + 4 = 8, 5 + 5 = 10. Doubles are easy to remember!

Question 3

What number pairs make 10? Name at least three.

Show Answer

Number pairs that make 10 include:

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

Question 4

How can knowing 4 + 4 = 8 help you find 4 + 5?

Show Answer

If you know 4 + 4 = 8, then 4 + 5 is just one more. So 4 + 5 = 9. This is called "doubles plus one" and it helps you add faster!

🚀 Next Steps

  • Practice every day: Try adding numbers in your head whenever you can - counting toys, snacks, or anything!
  • Learn your doubles: Memorize all the doubles from 1+1 to 10+10.
  • Time yourself: See how many addition problems you can solve in one minute.
  • Play math games: Card games and dice games are great for practicing quick addition.
  • Keep learning: Move on to Quick Subtraction to learn fast subtraction tricks!