Variables in algebra are like puzzle pieces that stand for numbers we don’t know yet. We often use letters like $x$, $y$, or $z$ to represent these unknowns. This makes it easier to create formulas and solve problems, even when we don't have all the information.

Why Variables Matter:

1. Flexibility: They let us write one equation that can apply to many different situations.
2. Generalization: You can find answers that work in lots of cases.

Example:

Let’s look at the equation $x + 3 = 7$.

In this case, $x$ is the variable. To figure out what $x$ is, we can subtract $3$ from both sides of the equation:

$$x + 3 - 3 = 7 - 3 \\ x = 4$$

Getting to know variables is important because they set the stage for understanding more complicated math concepts.