分數化百分數

1. 5分之2
=2/5 x 100%
= 40%
2. 2又500分之45
=(2*500+45)/500 * 100%
= 1045/5%
=209%
3. 3又25分之6
=(3*25+6)/25 * 100%
= 81/25 * 100%
= 81*4%
= 324%
4. 400分之64
= 64/400 * 100%
=64/4 %
= 16%

1. 2/5=2/5 x 2/2=4/10 (把分母變成10的指數)
=0.4
0.4 x 100%=40%

2. 2 x 45/500
=2 x 45/500 x 2/2
=2 x 90/1000
=2 x 0.09
=0.18
0.18 x 100%=18%

3. 3 x 6/25
=3 x 6/25 x 4/4
=3 x 24/100
=3 x 0.24
=0.72
0.72 x 100%=72%

4. 64/400
=64/400 x 2.5/2.5
=160/1000
=0.16
0.16 x 100%=16%

2007-11-06 12:58:31 補充：
唔好意思, 把所有乘變成加(除咗x100%外)即2. 2 0.09=2.092.09 x 100%=209%3. 3 0.24=3.243.24 x 100%=324%

1)2/5=20%

2)2又500分之45
=2又9/100
=209%

3)3又25分之6
=3又6/25
=324%

4)400分之64
=64/400
=16/100
=16%