帮我做下一道六年级简便运算题目99.9×98+(0.8-3/5)×999

来源:学生作业学帮网 编辑:学帮网 时间:2024/07/03 05:07:06

帮我做下一道六年级简便运算题目
99.9×98+(0.8-3/5)×999

99.9×98+(0.8-3/5)×999
=99.9×98+0.2×999
=999×9.8+999×0.2
=999×(9.8+.0.2)
=9990

999*9.8+(0.8-0.6)*999
=999*(9.8+0.2)
=9990

99.9×98+(0.8-3/5)×999
=999*9.8+999*0.2
=999*(9.8+0.2)
=9990

99.9×98+(0.8-3/5)×999
=99.9*98+0.2*10*99.9
=99.9*98+2*99.9
=99.9*(2+98)
=9990