[1]2,8乘[7分之1加上28分之3].[2]101乘102分之99 [3]55000除25除4 [4]23乘39分之

[1]2,8乘[7分之1加上28分之3]
=2.8X1/7+2.8X3/28
=0.4+0.3
=0.7
[2]101乘102分之99
=(102-1)X99/102
=102X99/102-1X99/102
=99-99/102
=98又34分之1
[3]55000除25除4
＝55000X25X4
=55000X(25X4)
=55000X100
=5500000
[4]23乘39分之14加14乘39分之16
=23X39分之14+16X39分之14
=39分之14X(23+16)
=39分之14X39
=14