When we use **algebra**, we use letters to stand for numbers that we are trying to find.

Algebra is like a language with its own rules.

* a* stands for a number.

* a + 2* is 2 more than the number.

* a - 7* is 7 less than the number.

* 5a* is 5 times the number.

*(N.B. We don't use the × sign in algebra because it looks like the letter x.)*

* a/4* or

*is a quarter of the number or the number divided by 4.*

**¼a***(N.B. We don't use the ÷ sign in algebra.)*

**Example**

I think of a number.

I double it and take away 5.

Then I add this to half the original number.

I get 20.

Write this using algebra.

Use * n* for the number I think of.

**Answer**

* n *is the number I think of.

Double it to get **2n**

Take away 5 to get** 2n - 5**

Then add this to* ½n* to give

**2n - 5 + ½n**This equals **20**

So we write:

**2n - 5 + ½n = 20**

Phew! It looks complicated but the important thing is to take it slowly, one step at a time.

Do you think you could give it a try?

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