Water is an important part of natural resources. Fresh water resources on land only account for 2.53% of the total water body on the earth's surface, and most of them (about 70%) are solid glaciers, which are difficult to use. At present, the fresh water resources that are relatively easy to use for humans are mainly river water, lake water, and shallow surface water, and their reserves account for about 0.3% of the total fresh water resources in the world. From the perspective of the water cycle, the total amount of fresh water resources on the earth is about 300000 cubic meters. How much fresh water resources can really be easily utilized?
水是自然资源的重要组成部分，陆地上的淡水资源只占地球表面水体总量的2.53%，其中大部分(约70%)是固体冰川，很难加以利用．目前人类比较容易利用的淡水资源主要是河流水、湖泊水、浅层地表水，储量约占全球淡水资源总量的0.3%．从水循环观点看，地球淡水资源总量约为300000万立方米，真正能容易利用的淡水资源约为多少？
<gadget id="calculator">0.3 / 100</gadget>
<output>0.003</output>

<gadget id="calculator">300_000 * 0.003</gadget>
<output>900</output>

<result>900</result>