遞等式計算(要巧算) 2.7×4.3+27×0.48+0.27×8

遞等式計算(要巧算) 2.7×4.3+27×0.48+0.27×8

2.7×4.3+27×0.48+0.27×8
= 2.7×4.3 + 2.7×4.8 + 2.7×0.8
= 2.7×(4.3 + 4.8 + 0.8)
= 2.7×(10 - 0.1)
= 27 - 2.7 = 24.3