Do grandchildren inherit from their grandfather if their mother died before him?

Grandchildren are either children of sons or daughters. Children of daughters do not inherit from their grandfather. As for children of sons, they inherit provided that the grandfather has no sons. If any of his sons exist, then the grandchildren do not inherit, whether their father is alive or deceased. The inheritance is distributed among the living heirs at the time of the deceased's death. Grandchildren who do not inherit can receive something in two ways: either the grandfather bequeaths to them a third of his estate or less, based on the verse: "It is prescribed for you when death approaches one of you, if he leaves behind good, that he make a will for parents and relatives in kindness—a duty upon the righteous" (Al-Baqarah/180). Or their uncles can give them something from their share. However, calculating the share of the deceased parent and giving it to the grandchildren has no basis in Islamic law.