有效數(shù)字:
因?yàn)?img src="https://newimg.ppkao.com/2019-09/shihuilin/2019091211391623188.jpg" />所以x=2.7有兩位有效數(shù)字;
因?yàn)?img src="https://newimg.ppkao.com/2019-09/shihuilin/2019091211393944052.jpg" />所以x=2.71亦有兩位有效數(shù)字;
因?yàn)?img src="https://newimg.ppkao.com/2019-09/shihuilin/2019091211395752649.jpg" />所以x=2.718有四位有效數(shù)字;