★456+542= ★900-807=
62÷9= 38÷6= 187+214-321=
验算:
5.2÷0.04= 1.32+0.8= 8 ÷8= 25+7.5=
51.51÷51= + ÷ = 1.5×2÷1.5×2= 149÷30≈