What is algebra?

Algebra is like having a secret tool to solve puzzles using numbers and letters.

Imagine you have 3 apples, and someone gives you more apples, but you don’t know how many yet. You could call that unknown number x. So now you have 3 + x apples. If later you find out you have 7 apples total, you can figure out what x is, it’s like solving a little mystery.

Think of letters in algebra as placeholders, they're like empty boxes waiting to be filled with numbers. When you see 2 + x = 5, it means "something plus 2 equals 5," and x is the number that fills the box.

You can solve these puzzles by doing things to both sides of the equation, just like balancing a seesaw. If you take away 2 from one side, you do it to the other too:

2 + x - 2 = 5 - 2

That leaves x = 3, and now your mystery is solved!

Algebra helps us find answers when we don’t know all the numbers at first, like figuring out how many cookies were in a jar before someone ate some.