(1)24.68+(6.35-4.68), =24.68-4.68-6.35, =20-6.35, =13.65; (2)82.9-13.68-2.32, =82.9-(13.68+2.32), =82.9-16, =66.9; (3)4.2×99+4.2, =4.2×(99+1), =4.2×100, =420; (4)48×1.25, =6×(8×1.25), =6×10, =60; (5)2.5÷(0.5×0.25), =2.5÷0.5÷0.25, =5÷0.25, =20; (6)0.065×430+65×0.57, =65×(0.43+0.57), =65×1, =65. |