1 -56%= 8.4÷0.7= ×99+ = ×( )=25
18÷ = 4.9× = 10÷10%= 0.02:0.5=
①17.8-20.4×
②25%× + ÷
③2.8× ÷ 0.52+
④23× - ×32
⑤ ÷ ×28×45
⑥4028×