⑴570÷30=
220×40=
318÷3=
278-49-51=
⑵398+102=
25×80=
104×7=
15×6÷15×6=
①123×26+26×77
②125×12×8
③329+165+235+271
④216÷[3×(35-17)]
9×9+19=9×9+9+10=9×(9+1)+10=9×10+10=(9+1)×10=10×10= 100
99×99+199