1.5×102=1.5×2×51=3×102=3061.5×0.7×0.8=1.5×0.8×0.7=1.2×0.7=0.842.7×3.7+0.37×73=2.7×3.7+3.7×7.3=3.7×(2.7+7.3)=3.7×10=37
