2.56+(7.39+4.28-10) 3.999+0.999+2.999+9.9 用简便方法计算

来源:学生作业学帮网 编辑:学帮网 时间:2024/06/17 22:45:21

2.56+(7.39+4.28-10) 3.999+0.999+2.999+9.9 用简便方法计算

2.56+(7.39+4.28-10)
=2.6-0.04+7.4-0.01+4.3-0.02-10
=14.3-10-0.07
=4.3-0.07
=4.23
3.999+0.999+2.999+9.9
=4-0.001+1-0.001+3-0.001+10-0.1
=18-0.103
=17.897