脱式计算①0.125×3.2×0.5②8.25+56÷32﹣1.25③5.42×7.6+3.4×5.42﹣5.42④2.5×(6.2﹣2.6)×0.4⑤15.6÷[(20.75﹣4.5)×0.4].
估算: 42÷5≈41÷2≈47÷5≈48÷2≈
估算: 39÷5≈40÷2≈41÷4≈42÷5≈
估算: 89÷5≈87÷2≈88÷3≈87÷9≈
估算: 19÷5≈76÷5≈87÷5≈78÷5≈
估算: 69÷5≈28÷5≈71÷7≈72÷5≈