5.07-2.8= 34÷4= 1- = ∶ =
180÷6= += ÷3= ×=
6﹣3.3= 2.2+3.57= ﹣= 39.5÷8≈(估算)
0.125×4= ×12= := 8×÷8×=
0.125×8= 4.5÷5= 3.55+2.45= 6297÷9≈
299×7≈
-= += ×5÷×5= 4÷0.01×0.1=
4÷-1= 100×9.8+0.2= 15.4﹣(5.4﹣4.5)= 0.15:0.3=
步骤:
结论1:
结论2: