易經和三十六計The Book of Change and The Thirty Six Strategies

六六三十六，數中有術，術中有數。 陰陽燮理，機在其中。機不可設，設則不中。

Six times six is thirty six. When we calculate the pros and cons of a situation, we need strategies. When we use strategies we must make calculations. The universal law of change is such. Opportunities are found in every situation. When planning a strategy, one must consider benefit. If there is no benefit, the strategy is not useful.