Decimal fractions which are of the following type can be converted to rational form.
When the number of numerals in the decimal part is fixed.
When a certain sequence of numerals in the decimal part repeat (or recur) infinitely)
Type A & B
Type C
There also exist numbers whose decimal part contains numerals which neither continue infinitely nor display any pattern. Such numbers cannot be written in rational form as “a/b”. We will study such numbers, which are called “irrational numbers”, in a subsequent chapter.