<<<<<
6×7=42
66×67=4422
666×667-444222
6666×=
①95÷23=
②510÷87=
③288÷36=
④358÷52=
⑤6400÷80=
⑥*850÷40=
①0.4x=3.6
②x﹣x=70
③1.6:x=0.8:0.4
④=