675+335
1000-583985-583 955-388955-369
256+365960-385 695-236+121747-329
28+35= 36+72= 73-28=
680-80= 500+400= 370+200=
607-500= 90+650= 750-90=
①864-698=
②389+577=
③※945-658=
④※356+379=