The document discusses fractions and their properties. It defines fractions as numbers of the form p/q where p and q are natural numbers. Fractions represent parts of a whole, for example 3/6 represents 3 out of 6 equal slices of a pizza. The numerator is the number on top and represents the parts, while the denominator on bottom represents the total parts of the whole. Equivalent fractions like 1/2, 2/4, and 3/6 represent the same quantity. Dividing the numerator and denominator by a common factor results in an equivalent fraction. The denominator of a fraction cannot be zero, as this results in an undefined fraction.