The Qur’an mentions about inheritance in many places, in
Surah Al Baqarah chapter 2 verse 180
Surah Al Baqarah chapter 2 verse 240
Surah Al Nisa chapter 4 verses 7 to 9
Surah Al Nisa chapter 4 verses19 and 33
Surah Al Ma‘idah chapter 5 verses 105 and 108
Regarding the share of inheritance it is clearly given in Surah Nisa chapter 4 verse 11, 12 and 176.
Let us examine the verses quoted by Arun Shourie, i.e. Surah Nisa chapter 4 verses 11 and 12:
"Allah (swt) (thus) directs you as regards your children’s(inheritance): to the male, a portion equal to that of two females: if only daughters, two or more, their share is two-thirds of the inheritance; if only one, her share is a half.
For parents, a sixth share of the inheritance to each, if the deceased left children; if no children, and the parents are the (only) heirs, the mother has a third; if the deceased left brothers (or sisters) the mother has a sixth. (The distribution in all cases is) after the payment of legacies and debts. Ye know not whether your parents or your children are nearest to you in benefit. These are settled portions ordained by Allah; and Allah is All-Knowing, All-Wise."
"In what your wives leave, your share is a half, if they leave no child; but if they leave child, ye get a fourth; after payment of legacies and debts. In what ye leave, their share is a fourth, if ye leave no child; but if ye leave a child, they get an eighth; after payment of legacies and debts." [Al-Qur’an 4:11-12]
Islam explains the law of inheritance in great detail. The broad and basic outline is given in the Qur’an and the minute details are given in the Ahadith i.e. the tradition and sayings of the Prophet (pbuh).
A person can spend his full life only on the research of the Islamic law of inheritance with its various permutations and combinations. Arun Shourie expects to know the law only by superficially reading two verses of the Qur’an without knowing the criteria.
It is similar to a person who wants to solve a mathematical equation but does not know the basic rule of mathematics, i.e. BODMAS which says that in a mathematical equation, irrespective of which mathematical sign appears first, you will first solve BODMAS: 1st Brackets Off, 2nd Division, 3rd Multiplication, 4th Addition and 5th Subtraction. If Arun Shourie does not know mathematics and first does multiplication then subtraction, then brackets off, then division and finally addition, the answer that he will obtain is bound to be wrong.
Similarly, when the Qur’an mentions the law of inheritance in Surah Nisa chapter 4 verses 11 and 12, even though the children’s share is mentioned first and then that of the parents and spouses, according to the law of inheritance in Islam after paying off the debts and liabilities first, the share is given to the spouses and the parents depending on whether the deceased has left children or not, and whatever portion of wealth is remaining is divided between the sons and the daughters according to their respective shares.
So where does the question arise of the total coming to more than one? So it is not Allah who does not know mathematics but it is Arun Shourie himself who is ignorant about mathematics.