①c+b=a
②d÷f=e…g
③10d÷10e=10f…10g
④e×f+g=d
⑤(e+g)×f=d
⑥(d-g)÷f=e
⑴□+◯=△
⑵◯-△=□
⑶■÷●=▲
⑷■×▲=●
①◎−○=★ ②★+◎=○ ③□÷▲=◇ ④◇×▲=□