以下的數點計

所有帶分數= 整數部分+分數部分 而分數除法是把除數顛倒 再給除數相乘
例如: 1又3分一 = 1+1/3 = 4/3 (通分母相加得假分數)
3分2 除以 4分3 = (2/3)/(3/4) = 3分2 乘3分4 = (2/3) (4/3) = 8/9


一又五分之一除四乘三分之二等於?
[(1+1/5)/4]x(2/3)
=[(6/5)/4]x2/3
= (6/20) x (2/3)
= 12/60
= 1/5

二十二又二分之一 乘五分之三減二十等於?

(22+1/2)x(3/5)-20
= (45/2)x(3/5)-20
= 135/10 - 20
= 135/10 - 200/10
= -65/10
= -6.5 或 負6又2分1


十又三分之二加十五又三分之一除三又四分之一等於?

這裡要先乘除後加減

(10+2/3) + (15+1/3)/(3+1/4)
= (32/3) + [(46/3)/13/4]
= (32/3) + [(46/3)(4/13)]
= 416/39 + 184/39
= 600/39
= 200/13
= 15+5/13 = 15又13分5

二又三分之一除(一又十分之三減四分之一)等於?

(2+1/3) / (1+3/10-1/4)
= (7/3) / (13/10-10/40)
= (7/3)/ (52/40-10/40)
= (7/3)/(42/40)
= (7/3)x(20/21)
= 140/63
= 20/9
= 2+2/9 = 2又9分2

2008-06-02 19:28:24 補充：
而分數除法是把除數顛倒 再給除數相乘 (誤) 漏了個被字
而分數除法是把除數顛倒 再給被除數相乘 (正)

2008-06-10 21:27:23 補充：
搞錯:是二十減(二十二又二分之一 乘五分之三)

20 - (22+1/2) x (3/5)
= 20 - (45/22 x 3/5)
= 440/22 - 27/22
= 413/22
= 18又17/22