29.7*0.8+0.3*0.2 =(30-0.3)*0.8+0.3*0.2 =30*0.8-0.3*(0.8-0.2) =24-0.3*0.6 =23.82 望采纳,谢谢!
90×29点8除以99 =9×298÷9÷11 =298÷11×(9÷9) =298/11
29.8÷9.5 =298 ÷ 95 ≈ 3.136 ≈3.14 竖式见图:
29.5×10.1-2.95=29.5×(10+0.1)-2.95=29.5×10+29.5×0.1-2.95=295+2.95-2.95=295
谢谢望采纳