420+391=
215+409=
426+778=
724-95=
971-600=
942-163=
57+=803
249+=789
345+=950
83×7=
9×48=
774×4=
459÷3=
504÷8=
918÷6=

-267=893-453
149+154+404+187=
790-279=+331
501+328+289-918=
229++395=993
468+470-298-309=
278+-583=467
999-252-122-431=