（1）原式=34+555

                =589

   （2）原式=65+84-38

                =149-38

                =111

（3）原式=185-28+14

                =157+14

                =171（4）原式=320-320÷16

                =320-20

                =300

（5）原式= 480-180+120

                =300+120

                = 420（6）原式=623+8×5

                =623+40

                =663