What is algebra?Why use letters?

Sometimes in algebra you will use the initial letter of a word to stand in for that word.

For example, the area of a square can be found by multiplying the length by the length.

You could write this as l x l

Or you could write it as l²

Even if you are working with different squares, with different length of side, you can use l x l or l² to find the answer every time.

Using more than one letter

Sometimes you might have more than one unknown value. For example, the area of a rectangle can be found by multiplying the length by the breadth. If you wrote this with just question marks or empty boxes it would look like this:

? + ? or +

Which is which? It’s confusing.

You could use l for length and b for breadth instead:

l x b

The letters make it clearer which is which.

Again, the values can change so that you can use this for lots of different rectangles.