一道题解法的繁简，不仅取决于题目本身，还取决于解法的选择．解法选择得合理，将能变繁为简，提高解题速度，下面以密度计算为例加以说明．一、灵活选用单位例１不用天平，只用量筒，你能不能量出１００克酒精？思路１按国际单位制统一单位后求解．即质量单位用千克，密度的? The complexity of a solution to a problem depends not only on the topic itself but also on the choice of solution. Reasonable choice of solution, will be able to become simple and increase the speed of problem solving, the following density calculation as an example to illustrate. First, the flexible choice of the unit case 1 without scales, only the use of the barrel, you can not produce 100 grams of alcohol? The idea 1 is solved by the unified unit of international system. That is, the unit of mass is kilograms, the density?