①31×6≈
②49×5≈
③19×3≈
④82×6≈
10﹣6.8= ﹣ = 35×1%= 1.25×24= 5× ÷5× =
0.42= 10÷0.02= 5a×7a= 1÷3= 1﹣1÷6=
① ×[0.75﹣( ﹣25%)]÷1.25
②6.37×1.25﹣1 +4.63×125%
③7.09× +0.225×6﹣60%×0.64
④ ×3+ ×25+ ×
⑤
⑥