Qur'anic verses - Case 4:

A man died leaving a wife, a son, a duaghter and parents:

(1) The inheritance is divided into equal shares:

no. of shares, say = 24 x (2 x S + D)

(where, S = no. of sons; D = no. of daughters)

in this case,
24 x (2 x 1 + 1) = 72 shares

(2) The wife, according to verse (4:12), inherits one eighth of the whole inheritance:

wife's shares = 1/8 x 72 = 9

(3) Each parent, according to verse (4:11), inherits one sixth of the whole inheritance:

each parent's shares = 1/6 x 72 = 12

For parents, a sixth share of the inheritance to each, if the deceased left children.
[Qur'an 4:11]

(4) The remaining inheritance is divided between the children in accordance with verse (4:11), such that the male takes twice the share of a female:

(remaining = 72 - 9 - 12 - 12 = 39 shares)

daughter = 39 / (2 x S + D) = 39 / 3 = 13 shares

son = 13 x 2 = 26 shares

God (thus) directs you as regards your Children's (Inheritance): to the male, a portion equal to that of two females.
[Qur'an 4:11]