Step-by-step explanation:
After the death of Muhammad's mother Aminah bint Wahab, Muhammad as a child was taken into the care of his grandfather, Abd al-Muttalib. When Muhammad reached eight years of age, Abd al-Muttalib died. One of Muhammad's uncles was to take him in. The oldest, Al-Harith was not wealthy enough to take him in.
Answer:
He was Eight.