1. What is the difference between when a fraction is written in the form 1530 and when it is written 15/30?

There is no difference. Some people use one way and some people use the other.

2. Is it better to write a number as a percentage or as a decimal?

Although each way represents the same number, it is often more CONVENIENT to use one form rather than another.
e.g. When talking about a wage rise or an exam mark, we often use a percentage.
If we are measuring the length of a piece of wood we use decimals rather than fractions

 

3. How is the fraction "one third" written as a decimal?

When doing the division 1.0000 ÷ 3, the answer 0.3333... is obtained.
To indicate that the "3" repeats forever a point is placed above the first 3 i.e. Y7_Conversions_FAQ_02.gif

Usually with fractions that repeat we leave them in fraction form rather than as a decimal.

4. How are percentages changed into decimals or fractions?

Changing percentages into decimals or fractions always involves either multiplying or dividing by 100.

5. Is it acceptable to write fractions such as "one half" as 1530 ?

While 1530 is equivalent to 12 final answers should always be given in their simplest form.