There was a scientist doing some research on a frog. The man says "Jump frog Jump!" The frog jumps 20 feet.

Then he writes it down in his book, cuts off one leg, and then says "Jump frog Jump!" The frog can only jump 15 feet.

The man writes this down in his book, cuts off another leg, and says "Jump frog Jump!" The frog can only jump 10 feet.

The man writes this down in his book, cuts off a third leg, and says "Jump frog Jump!" The frog can only jump 5 feet.

Writes this down in his book and cuts the frogs last leg off. Then he says "Jump frog Jump!" The frog just sits. He repeats a little louder "Jump Frog Jump!!" The frog just sits. One more time really loud "JUMP FROG JUMP!!!" The frog just sits.

The scientist writes in his book: Cut off one leg frog jumps, two legs frog jumps, three legs the frog still jumps, but four legs and the frog becomes deaf.