Section 1
Where Did the Equal Sign Come From?
Have you ever seen this sign: = ? It is called the equal sign. People have been using it for a very long time! A man named Robert Recorde made it up hundreds of years ago. He was a math teacher who got tired of writing the words "is equal to" over and over. So he drew two short lines that are the same length. He thought two lines that look alike would be a great way to show that two things are the same.
Long, Long Ago
1557
After 1557
Today
So the big question is: what does this little sign really mean? Let's find out!
Section 2
Big Ideas About the Equal Sign
The equal sign = means "is the same as." When you see it, it tells you that what is on the left side and what is on the right side have the same value. Think of it like a balance or a seesaw — both sides must match!
"Same As"
Not Just "The Answer"
Works Both Ways
True or False
KEY TAKEAWAY
Section 3
See It: The Balance Scale
Look at the picture below. It shows a balance scale. On the left side we put 2 + 3. On the right side we put 5. Since 2 + 3 makes 5, both sides are the same. The scale is balanced! That means the equation 2 + 3 = 5 is TRUE.
Count the blocks! On the left there are 2 blocks and 3 blocks. That is 5 blocks altogether. On the right there are 5 blocks. Both sides have 5. The scale stays flat. The equation is true!
Section 4
How the Equal Sign Works
Here is the big rule: add up (or subtract) what is on the left, add up (or subtract) what is on the right, then check if they match. If they match, the equation is true. If they don't, it is false.
Addition Equation
Left side: 3 + 4 = 7. Right side: 7. They match! ✓ TRUE
Subtraction Equation
Left side: 8 − 3 = 5. Right side: 5. They match! ✓ TRUE
A False Equation
Left side: 2 + 1 = 3. Right side: 5. They do NOT match! ✗ FALSE
Remember, the equal sign can also be at the start! Look at this: 6 = 4 + 2. The left side is 6. The right side is 4 + 2, which is 6. They are the same! So this is true. The number does not always have to be on the right.
Number on the Left Side
Left side: 6. Right side: 4 + 2 = 6. They match! ✓ TRUE
Section 5
True or False? Let's Practice Reading Equations
An equation is a math sentence that has an equal sign. Your job is to figure out if each equation is true or false. Let's look at a bunch of them in a chart!
| Equation | Left Side | Right Side | Same? |
|---|---|---|---|
4 + 1 = 5 | 4 + 1 = 5 | 5 | TRUE ✓ |
7 − 2 = 5 | 7 − 2 = 5 | 5 | TRUE ✓ |
3 + 3 = 7 | 3 + 3 = 6 | 7 | FALSE ✗ |
5 = 2 + 3 | 5 | 2 + 3 = 5 | TRUE ✓ |
9 − 4 = 6 | 9 − 4 = 5 | 6 | FALSE ✗ |
8 = 8 | 8 | 8 | TRUE ✓ |
Here is another picture. This time, the scale is NOT balanced. The left side has more than the right side. That means the equation is false.
3 + 3 makes 6, but the right side says 4. Six and four are NOT the same. So 3 + 3 = 4 is false. The left side is heavier!
Section 6
Worked Example: Step by Step
Let's solve one together, nice and slow. We want to find out if this equation is true or false:
Equation to Check
Worked Example: 5 + 2 = 9 − 2
- 1
Step 1 — Look at the left side
The left side says 5 + 2. Let's add those up. Five plus two is 7. So the left side equals 7. - 2
Step 2 — Look at the right side
The right side says 9 − 2. Let's subtract. Nine take away two is 7. So the right side equals 7. - 3
Step 3 — Compare!
The left side is 7. The right side is 7. Are they the same? Yes! 7 equals 7. - 4
Step 4 — Answer
Since both sides are the same, the equation 5 + 2 = 9 − 2 is TRUE! Great job!
Section 7
Tricky Parts to Watch Out For
Some kids think the equal sign means "the answer is coming next." But that is not quite right! The equal sign means both sides are the same. Here are some tricky things to remember.
| What Some Kids Think | What Is Really True |
|---|---|
| = means "the answer goes here" | = means "is the same as" |
| The number must always be on the right (like 3 + 2 = 5) | The number can be on either side! (5 = 3 + 2 is fine) |
| You can only have one number on the right | You can have adding or subtracting on BOTH sides! (2 + 3 = 1 + 4) |
| If I see =, I need to do something | Sometimes you just check: is this true or false? |
KEY TAKEAWAY
Section 8
What Comes Next?
Now that you know what the equal sign means, you are ready for even more fun math! Soon you will learn about missing numbers. These are equations where one part is hidden, and you have to figure out what goes there.
| What You Know Now | What You'll Learn Next |
|---|---|
| Check if 3 + 2 = 5 is true or false | Find the missing number: 3 + ? = 5 |
| Both sides of = must be the same | Use that rule to solve for unknowns |
| Use adding and subtracting in equations | Use bigger numbers and more steps |
You are building a strong math brain! Every time you check if an equation is true or false, you are thinking like a real mathematician. Keep going!
Section 9
Practice Problems
Try these on your own! Think about each one carefully. When you are ready, click the button to see the answer.
Question 1: Problem 1 — What Does It Mean?
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Question 2: Problem 2 — True or False?
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Question 3: Problem 3 — A Little Trickier
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Question 4: Problem 4 — Both Sides Have Math
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Question 5: Problem 5 — Think Hard!
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Summary
Let's Remember What We Learned
Summary
The equal sign (=) means "is the same as." It does NOT mean "the answer goes here." When you see an equation like 3 + 4 = 7, the equal sign is telling you that the left side and the right side have the same value. Think of it like a balance scale — both sides need to hold the same amount to stay flat.
To check if an equation is true or false, solve the left side, solve the right side, and compare them. If they match, it is true. If they don't, it is false. Numbers can go on either side of the equal sign, and there can be adding or subtracting on both sides. You are now an equal-sign expert!