Fractions
A fraction represents a part of a whole. In EPSO, fractions appear every time you divide one number by another.
Practice This ConceptUnderstanding Fractions
A fraction is simply one number divided by another. The top number (numerator) is the part. The bottom number (denominator) is the whole. When you calculate "exports as a percentage of GDP", you are creating a fraction: exports ÷ GDP.
Formula
$\frac{numerator}{denominator}$
Key Rules
- The numerator (top) is what you are measuring
- The denominator (bottom) is what you are comparing against
- Flipping top and bottom gives the inverse — a completely different answer
- To convert a fraction to a percentage, multiply by 100
Examples in Action
1
121 ÷ 1208
=
0.1001
GDP change of 121 out of starting value 1208
2
18.7 ÷ 140.6
=
0.133
Research budget as fraction of total EU budget
3
3 ÷ 4
=
0.75
Three quarters — 75%
Common Errors
- Putting the wrong number on top vs bottom
- Forgetting that 1/4 is smaller than 1/3 (larger denominator = smaller value)
- Not converting to percentage when required (forgetting × 100)
Pro Tip
Always ask yourself: "what is the PART and what is the WHOLE?" The part goes on top.