How many parts of a whole
Slice a pizza, and we get fractions:
The top number says how many slices we have.
The bottom number says how many equal slices the whole pizza was cut into.
Have a try yourself:
Some fractions may look different, but are really the same, for example:
It is usually best to show an answer using the simplest fraction ( 1/2 in this case ). That is called Simplifying, or Reducing the Fraction
Numerator / Denominator
We call the top number the Numerator, it is the number of parts we have.
We call the bottom number the Denominator, it is the number of parts the whole is divided into.
You just have to remember those names! (If you forget just think "Down"-ominator)
It is easy to add fractions with the same denominator (same bottom number):
Adding Fractions with Different Denominators
But what about when the denominators (the bottom numbers) are not the same?
We must somehow make the denominators the same.
In this case it is easy, because we know that 1/4
is the same as 2/8 :
There are two popular methods to make the denominators the same:
(They both work nicely, use the one you prefer.)
Other Things We Can Do With Fractions
We can also:
Visit the Fractions Index to find out even more.