Molecules refer to numbers written above the fractional line in a fraction, and numbers or algebraic expressions written below the fractional line in a fraction are called denominators. The numerator and denominator of a fraction are multiplied or divided by the same non-zero number, and the obtained fraction is equal to the original fraction.
A fraction is the ratio of an integer a to a positive integer b that is not equal to an integer. The essence of a fraction is a fraction indicating that one number is another number, or the ratio of one event to all events.