There are also *= and /= operators that multiply and divide by their right hand sides before assigning. In practice you almost never see these because of the speed at which variables making use of them go to either zero or Inf. If you don't believe me consider the following cautionary tale.

Many centuries ago in India a very smart man is said to have invented the game of chess. This game greatly amused the king, and he became so enthralled with it that he offered to reward the inventor with anything he wished, up to half his kingdom and his daughter's hand in marriage.

Now the inventor of the game of chess was quite intelligent and not a little greedy. Not being satisfied with merely half the kingdom, he asked the king for the following gift:

"Mighty King,he said, "I am but a humble man and would not know what to do with half of your kingdom. Let us merely calculate my prize as follows. Put onto the first square of the chessboard a single grain of wheat. Then onto the second square of the chessboard two grains, and onto the third square of the chessboard twice two grains, and so on until we have covered the board with wheat.

Upon hearing this the king was greatly pleased for he felt he had gotten off rather cheaply. He rapidly agreed to the inventor's prize. He called for a bag of wheat to be brought to him, and when it arrived he began counting out wheat. However he soon used up the first bag and was not yet halfway across the board. He called for a second, and a third, and more and more, until finally he was forced to admit defeat and hand over his entire kingdom for lack of sufficient wheat with which to pay the inventor.