# Basics of Percentage

Basics of Percentage:

The word percentage or per cent means for every one hundred. It is denoted by symbol %. Thus 10 % means 10 out of hundred or $$\frac{{10}}{{100}}$$.

Key Facts:
1. For converting a given percentage into a fraction, divide it by 100 or multiply by $$\frac{1}{{100}}$$.
i.e. 25% can be converted in to fraction by dividing it by 100,
Hence, 25% = $$\frac{{25}}{{100}}$$ = 0.25.

2. For converting a given fraction into percentage multiply it by 100. Thus,
.25 = .25 × 100 = 25%.

3. For converting one given quantity, say x as a percentage of another given quantity, say y find $$\frac{x}{y} \times 100$$ .

Concept of percentage change:

1. Absolute value change:
It is actual change in measured quantity. For instance, if sales in year 1 is Rs. 2500 crore and sales in year 2 is Rs. 2600 crore, then the absolute value of the change is Rs. 100 crore.

2. Percentage change:
It is given by,
Percentage change
\eqalign{ & = \frac{{{\text{absolute}}\,{\text{change}}}}{{{\text{original}}\,{\text{quantity}}}} \times 100 \cr & = \frac{{100}}{{2500}} \times 100 \cr & = 4\% \cr}