This is the answer.
Cut the gold in 3 parts 1 cm, 2 cm & 3 cm,
1st day - give 1 cm
2nd Day - give 2 cm and take 1 cm back
3rd day - give 3 cm and take 2 cm back
4th day - give 1 cm
5th day - take back 1 cm and give 2 cm
6th day - give 1 cm
after that kill the man and eat him for dinner. You get the gold back too. lol ;)