考点:小数的读写、意义及分类
专题:小数的认识
分析:0.9的计数单位是0.1,它里面有9个0.1;
0.09的计数单位是0.01,它里面有9个0.01;
0.68的计数单位是0.01,它里面有68个0.01;
求82个0.001是多少,用0.001×82,由此解答即可.
解答:
解:0.9里面有9个0.1,0.09里面有9个0.01;0.68里面有68个0.01,0.082里面有82个0.001,
故答案为:9,9,68,0.082.
点评:此题主要考查小数的意义和计数单位,应明确一位小数的计数单位是0.1,两位小数的计数单位是0.01,三位小数的计数单位是0.001.