直接写得数502﹣197= 8.01﹣2.1= 2.5×40= 0.33= 5.2÷0.125÷8== = = = 12.5÷(10%÷10)=
好朋友,牵牵手.
数学门诊.(把不对的改正过来) (1)1.7×0.31+0.69×1.7=1.7×(0.31+0.69)×1.7=1.7×1×1.7=2.89 改正:(2)0.25×12=0.25×(4×3)=0.25×4+0.25×3=1+0.75=1.75 改正:(3)3.5×103=3.5×100+3=350+3=353 改正:
用简便方法计算.(1)47×0.125×8(2)0.65×201(3)0.02×48.8×50(4)1.45×6.5+0.55×6.5(5)0.625×0.8×0.04×0.5(6)18.8×101﹣18.8.
算一算,比一比,每组中哪个算式的计算比较简便?(1)378+73+27(23×15)×4 (2)378+(73+27)23×(15×4)
你能用几种方法计算?2.5×4.419.5﹣1.9﹣2.9﹣3.9.