Fractions

• Proper Fractions -

• Improper Fractions -

• Rational Fractions -

Numerator - This is the number on the top
Denominator - This is the number on the bottom. The denominator of a fraction can never be zero. If it is then the fraction is undefined.
The denominator of a fraction can never be zero.

Converting Fraction to Decimal

divide the number above the line (numerator) by the number below the line (denominator)

Converting Fraction to Percentage

divide the number above the line (numerator) by the number below the line (denominator)
and then multiple by 100

Multiplying Fractions

Multiplying fractions is easier than adding them up.
Just multiply straight across the top and straight across the bottom.

Dividing Fractions

This is identical to multiplying except you need to flip the second fraction first.

Adding Fractions

To add fractions you need to find a common denominator.

but what if you have:

The most obvious common denominator is (b * d)

Exactly which common denominator you use will depend on the fractions you want to add together.
For example consider the fractions:

You could use the denominator (4 * 10) = 40

Alternatively you could use a smaller common denominator
For example you could use 20. Since both 4 and 10 go into 20.

How many times does 4 go into 20. 5 times
How many times does 10 go into 20. 2 times

Subtracting Fractions

To subtract fractions you need to find a common denominator

but what if you have:

The most obvious common denominator is (B * d)

Simplifying Fractions

At the end of a calculation you are often left with a complicated algebraic formula.
Not always but sometimes it is possible to cancel some of the fractions to give you a simpler answer.

For example, lets consider the fraction 50/100
This could be simplified
It could be written as 25/50 or 5/10 or 1/2

You can only simplify a fraction of the numerator and the denominator share a common multiple

Excel Fraction Number Format