第588题：the idea of a fraction

What is meant by two thirds? ( ).

A. $\dfrac{1}{3}$ B. $\dfrac{2}{3}$

C. $23$ D. $32$

One thing of any kind is a unit.

Two thirds is two of the three equal parts of a unit.

Such parts of aunit as two thirds, one third, three fourths, etc. , are called fractions.

A fraction is expressed by two numbers, one being called the numerator and the other the denominator.

The denominator is the number of equal parts into which the unit is divided. the numerator is the number of equal parts taken.

A fraction is expressed in figures by writing the numerator over the denominator, thus, $\dfrac{2}{3}$ ，$\dfrac{3}{4}$ ， $\dfrac{5}{8}$ .

When the value of a fraction is less than a unit it is a proper fraction. When its value is a unit or more than a unit, it is an improper fraction.

The numerator of a proper fraction is less then the denominator; and the numerator of an imporper fraction is equal to or greater then the denominator.

A Fraction is one or more of the equal parts of a unit.

The numerator and denominator are called the terms of a fraction.