Fractional unit is a mathematical term. Divide the unit "1" into several parts, and take one part, which is called decimal unit. That is, the numerator is 1, and the denominator is a positive integer fraction, also called unit fraction, which is called 1/n, and the unit fraction is also called "monomolecular fraction" and "Egyptian fraction". Fraction definition: divide the unit "1" into several equal parts, and the number representing one or several parts is called a fraction, for example,? The general form of m/n fraction is (M and N are integers, and the denominator n cannot be zero), N is the number of units divided equally, which is called the denominator of this fraction, and it is the number representing one of them, which is called the fractional unit, and M represents its number of units, which is called the numerator of this fraction, and the horizontal line in the middle (diagonal line in this paper) is called.