Drawing a diagram may be helpful.
Portion given to his son. Portion kept.
Try to find the amount the rancher gave to his son to find the total.
You can reason that the rancher gave his son half as much as he kept. Therefore, he gave his son 17 acres of land.
You can find the total by adding the portion the rancher gave to his son to the portion he kept for himself.
You can also solve this problem by asking yourself: Two thirds of what total amount is 34?
51 acres of land.