用简便计算0.1+0.2+0.3.+5.6+5.7
问题描述:
用简便计算0.1+0.2+0.3.+5.6+5.7
答
0.1+0.2+0.3.+5.6+5.7
=(0.1+5.7)+(0.2+5.6)+……+(2.8+3.0)+2.9
=5.8+5.8+……+5.8+2.9
=5.8×28+2.9
=165.3