2.81×5.84+7.19×5.84                  3.68+7.56-2.68

=5.84×〔2.81+7.19〕                   =3.68-2.68+7.56

=5.84×10                              =1+7.56

=58.4                                  =8.56

9.9×0.35+0.035                        3.82+2.9+0.18+9.1

=9.9×0.35+0.35×0.1                   =3.82+0.18+〔2.9+9.1〕

=0.35×〔9.9+0.1〕                     =4+12

=0.35×10                              =16

=3.5

1.25×〔5.28-4.3〕×80                 0.388+0.36+3.64

=〔1.25×80〕×〔5.28-4.3〕            =0.388+〔0.36+3.64〕

=100×0.98                             =0.388+4

=98                                    =4.388

5.17-1.8-3.2                           0.25×16.2×4

=5.17-〔1.8+3.2〕                      =0.25×4×16.2

=5.17-5                                =1×16.2

=0.17                                  =16.2

35.6-1.8-15.6-7.2                      320÷1.25÷8

=35.6-15.6-〔7.2+1.8〕                 =320÷〔1.25×8

=20-9                                  =320÷10

=11                                    32