Interesting Fractions

This is a folk tale from India. A man had 17 cows. Before he died, he told his sons that the eldest would get half the number of cows. to the second he bequeathed one third the number of cows and to the third he left one ninth the number of cows. After the father's death, the sons wondered how to divide the cows.
1/2 of 17 = 8.5. "How can we have eight and a half cows?" said the eldest son. They racked their brains but failed to find a solution.So the three sons went to the wisest man in the village and asked him to help out. "Take my cow and see if you can find a solution", said the wise old man. "But how can we deprive you of your one and only cow?" said the young men. When the old wise man kept on insisting the young men decided to take his cow. Now the division was quite easy as they had 18 cows.
"Half of 18 is nine, one third of 18 is six and one ninth of 18 is two" . so the three brothers got 9, 6 and 2 cows respectively.That totalled to 17 cows. And the one cow left behind was duly returned to the wise old man.

The story is good to introduce the concept of fractions. Also ask your class to think how this was possible?