(i) When the divisor is a whole number. Suppose we have to divide 7/9 by
4.
We know 7/9 = 28/36. This fraction means that the unit is divided into
36 equal parts, and 28 of the parts taken. If we divide the 28 parts by
4, we get 7 of them--_i.e._ 7/36. Hence 7/9 ÷ 4 = 7/36.
Therefore, to divide a fraction by a whole number, we multiply the
denominator by that number.
In the same way as already explained for multiplication, we cancel any
common factors contained in the divisor and the numerator. Hence, if the
numerator be exactly divisible by the divisor, we may divide a fraction
by a whole number by dividing the numerator by that number.