Early Math · Grade 1

The Equal Sign: True and False Number Sentences

Quick answer

The equal sign means "is the same as": the amount on one side matches the amount on the other. It does not mean "the answer comes next," so 5 = 4 + 1 and 6 = 6 are true, and 4 + 1 = 5 + 2 is false even though 4 + 1 makes 5. To check a number sentence, work out each side and see whether they match.

What you'll learn

  • Explain the equal sign as 'is the same as'
  • Decide whether an addition or subtraction sentence is true or false
  • Fill in a missing number so both sides match

Is the same as

The equal sign, ==, means “is the same as.”

Four and one is the same as five Two rows of dots lined up on the left. The top row has four blue dots and one orange dot. The bottom row has five blue dots. Both rows end at the same place. 4 + 1 5
Four and one is the same as five

4+14 + 1 is the same amount as 55. The two rows end at the same place. So we can write:

4+1=54 + 1 = 5

The answer can come first

5=4+15 = 4 + 1 is true too. It says that 55 is the same as 4+14 + 1. That is the same fact, read the other way.

6=66 = 6 is true as well. Both sides are 66.

Why both sides must match

Think of the equal sign as a seesaw that is level. It stays level only when both sides weigh the same.

So the equal sign does not mean “the answer comes next.” It means the left side and the right side are the same amount. A number sentence is true when they match and false when they do not.

True or false?

To check a number sentence:

  1. Work out the left side.
  2. Work out the right side.
  3. If they match, it is true. If not, it is false.

Worked examples

Common mistakes

Practice problems

  1. True or false: 6=66 = 6

    Answer

    True

    Full solution

    Both sides are 66, so they match.

  2. True or false: 9=10−19 = 10 - 1

    Answer

    True

    Full solution

    10−1=910 - 1 = 9. Both sides are 99.

  3. True or false: 5+1=6+15 + 1 = 6 + 1

    Answer

    False

    Full solution

    The left side is 66. The right side is 77. They do not match.

  4. True or false: 8−2=3+38 - 2 = 3 + 3

    Answer

    True

    Full solution

    The left side is 66 and the right side is 66. They match.

  5. True or false: 10=5+410 = 5 + 4

    Answer

    False

    Full solution

    5+4=95 + 4 = 9, and 99 is not the same as 1010.

  6. What goes in the box? □=7+2\square = 7 + 2

    Answer

    99

    Full solution

    The right side is 7+2=97 + 2 = 9. The left side must be 99 too.

  7. What goes in the box? 2+6=□+52 + 6 = \square + 5

    Answer

    33

    Full solution

    The left side is 88. What and 55 make 88? 3+5=83 + 5 = 8, so the box is 33.

  8. What goes in the box? 9−4=2+□9 - 4 = 2 + \square

    Answer

    33

    Full solution

    The left side is 9−4=59 - 4 = 5. 22 and what make 55? 2+3=52 + 3 = 5.

  9. True or false: 4+6=6+44 + 6 = 6 + 4

    Answer

    True

    Full solution

    Both sides are 1010. A sum turned around stays the same.

  10. Kai says 4+5=9+24 + 5 = 9 + 2 is true, because 4+54 + 5 is 99. What went wrong?

    Hint

    Work out the whole right side.

    Answer

    The right side is 1111, not 99. It is false.

    Full solution

    The left side is 4+5=94 + 5 = 9. The right side is 9+2=119 + 2 = 11.

    99 is not the same as 1111, so the sentence is false. Kai stopped at the 99 and did not look at the +2+ 2.

Frequently asked questions

What does the equal sign mean?

'Is the same as.' 3 + 2 = 5 says that 3 + 2 is the same amount as 5.

Can the answer come before the equal sign?

Yes. 5 = 3 + 2 is true, because 5 is the same as 3 + 2. Both sides are 5.

How do I know if a number sentence is true?

Work out the left side and the right side. If they are the same, it is true. If not, it is false.

Is 4 + 1 = 5 + 2 true?

No. The left side is 5 and the right side is 7. They do not match, so it is false.

What goes in the box in 3 + 5 = □ + 4?

4. The left side is 8, so the right side must be 8 too, and 4 + 4 = 8.

What to learn next

Standards alignment

This lesson covers the following Common Core State Standards for Mathematics.

  • CCSS.MATH.CONTENT.1.OA.D.7Operations and Algebraic ThinkingUnderstand the meaning of the equal sign, and determine if equations involving addition and subtraction are true or false.
For teachersTick to print a blank worksheet; leave it clear to print the lesson with the full answer key.