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Addition — 1st Grade Lesson

Students will add within 20, recall addition facts to 10, and use strategies like counting on and making ten.

1st Grade · Addition · ~20 min lesson

What is addition?

Addition is joining groups together to find the total. When you put 3 apples and 4 apples in one basket, you have 7 apples. The numbers you add are called addends, and the answer is the sum.

3 + 4 = 7 addend + addend = sum

Strategy 1: Count all

For small numbers, count every object one by one.

3 + 2: draw 3 dots, then 2 dots, then count them all: 1, 2, 3, 4, 5.

Strategy 2: Count on

Instead of counting everything from 1, start at the first number and count up.

3 + 4: start at 4, count on 3 more: 5, 6, 7 → 7.

Strategy 3: Make a ten

When adding to 8 or 9, make a ten first — it’s faster and builds number sense.

5 + 8 → 8 + 2 = 10, then 10 + 3 = 13.

Strategy 4: Doubles

Doubles are facts where both addends are the same: 1+1, 2+2, up to 10+10. Learn them and doubles-plus- one facts (6+7 = 6+6+1) come free.

DoublesSum
5 + 510
6 + 612
7 + 714
8 + 816

How to practice at home

  • Count everyday things: snacks, stairs, toys — “2 crackers plus 3 crackers is…?”
  • Finger counting on: hold up the first number, count on the rest.
  • Dominoes: pick a domino, add the two sides.
  • Fact flashcards: 2 minutes a day of fast recall to 10.

Practice with the exercises above, then download these free printable worksheets:

Practice Exercises

Try these on your own, then reveal the answer to check.

  1. What is 3 + 4?

    💡 Count on from 4: 5, 6, 7.

  2. What is 6 + 6?

    💡 A doubles fact.

  3. Find the missing number: 8 + ___ = 10

    💡 8 and 2 make a ten.

  4. What is 9 + 1?

    💡 9 and 1 make a ten.

  5. What is 5 + 8?

    💡 Make a ten: 8 + 2 = 10, then 10 + 3 = 13.

  6. Add three numbers: 2 + 3 + 4

    💡 Add 2 + 3 = 5, then 5 + 4 = 9.

Printable Worksheets

Put this lesson into practice with free, printable worksheets — each with an answer key.

Before You Start

  • Counting to 20
  • Recognizing numbers 0-10

Common Mistakes to Watch For

  • Counting objects twice when adding
  • Starting the count at 1 instead of counting on from the first number

What to Learn Next

Browse more Addition worksheets or explore all 1st Grade worksheets.

Related Worksheets

Preview of the Addition Facts to 10 Worksheet for 1st Grade
🔢Math Easy

Addition Facts to 10 Worksheet

Practice addition facts with sums up to 10, using a number line to count on.

1st Grade 10 min ✓ Answer key
Preview of the Addition Within 20 Worksheet for 1st Grade
🔢Math Standard

Addition Within 20 Worksheet

Practice addition facts with sums up to 20, with a number line to count on from the larger number.

1st Grade 12 min ✓ Answer key
Preview of the Missing Addends Worksheet for 1st Grade
🔢Math Standard

Missing Addends Worksheet

Find the missing addend that makes each addition sentence true.

1st Grade 10 min ✓ Answer key
Preview of the Make a Ten to Add Worksheet for 1st Grade
🔢Math Standard

Make a Ten to Add Worksheet

Add within 20 by making a ten first: take from one number to fill the other up to 10, then add the rest.

1st Grade 10 min ✓ Answer key

Frequently Asked Questions

What addition facts should a 1st grader know?

By the end of the year, most students should recall addition facts to 10 instantly and add within 20 using strategies like counting on and making ten.

What is the make-a-ten strategy?

When adding a number to 8 or 9, take part of the other number to make ten first. For 5 + 8: take 2 from the 5 to make 8 + 2 = 10, then add the remaining 3 to get 13.

Original & reviewed. Every worksheet is created in-house from a grade-level skill brief, checked for a correct answer key, and reviewed for grade-appropriateness. Our editorial policy.