17×10.5的簡便計算
17×10.5
=17×(10+0.5)
=17×10+17×0.5
=170+8.5
=178.5
17÷0.25÷6.8怎樣簡便怎樣算
17除以(0.25乘6.8)等於10
17/24*25有簡算方法嗎
17/24×(24+1)=17+17/24
7.8*1.17-7.8*0.17=(簡便計算)
7.8×1.17-7.8×0.17
= 7.8×(1.17 - 0.17)
= 7.8×1
= 7.8