Algebra

Formulas

Formulas in Words

If you are asked how many days there are in a week, you would find the answer easy - there are 7. How about the number of days in two weeks? Again, the answer is fairly straightforward - there are 14.

What happens when you are asked how many days there are in three weeks, or four or five? If you know the formula you could work this out.

1 week is 1 × 7 days = 7
2 weeks is 2 × 7 days = 14
3 weeks is 3 × 7 days = 21
4 weeks is 4 × 7 days = 28

So, the formula to work out the number of days is:
number of days = number of weeks × 7

Terms and Expressions 

In algebra, letters are used when numbers are not known.

Algebraic terms, like 2s or 8y, leave the multiplication signs…