67.58-(17.58+4.32) 1.25×2.5×(4×0.8)
7.6×3.4+6.6×7.6 4.2÷[(5.92-4.52)×0.2]
2.32×6.5+7.68×6.5
6.8×7.8÷3.9
7.2÷2.5÷4