Equal Sign — Definition, Formula & Examples
The equal sign (=) is the symbol that shows two things have the same value. When you write , the equal sign tells you that and represent the exact same amount.
The equal sign denotes a relation of equality between two mathematical expressions, asserting that the expression on the left side of the symbol has the same numerical value as the expression on the right side.
How It Works
The equal sign acts like a balance point. Whatever is on the left side must have the same value as whatever is on the right side. You can read as "is equal to" or "is the same as." For example, means the left side (4 plus 6) balances with the right side (10). The equal sign can also connect two expressions, like , because both sides equal 10.
Worked Example
Problem: Is the statement 9 + 6 = 15 true or false?
Step 1: Find the value of the left side by adding 9 and 6.
Step 2: Compare the left side to the right side. The left side equals 15 and the right side is 15. Both sides match.
Answer: The statement is true because both sides of the equal sign have the same value, 15.
Why It Matters
The equal sign is one of the first symbols you learn and one you will use throughout every math course, from basic arithmetic to algebra and beyond. Understanding that it means "same value on both sides" is essential for solving equations, where your goal is to find the number that makes both sides balance.
Common Mistakes
Mistake: Thinking the equal sign means "the answer comes next" instead of "both sides are the same."
Correction: The equal sign is not an instruction to calculate — it states that the left side and the right side have the same value. For instance, is just as correct as .