He died and left behind a son and three daughters; the estate includes five apartments – how should they be shared out?
If your father died and left behind a son and three daughters, and he did not leave behind any other heirs, then the estate is to be divided among you, with the male getting the share of two females.
So the son is like two daughters; the estate should be divided into five portions, of which the son takes two.
If the father left behind five apartments, and they are equal in size and value, or the heirs agree to the differences in size and value, then the son should take two apartments and each daughter should take one.
If the son agrees to give one apartment to be kept for the family, then he may do so. If they all agree to leave this apartment (for the use of the entire family) and divide the four others among themselves, they may do so and the son should take compensation from his sisters for the fifth apartment that he gave up.
What matters is understanding the principle, which is that the estate in this case is to be divided into five parts, because the male is equivalent to two females. But the heir may donate his share or part of it to whoever he wants.
And Allah knows best.