除以16, 是先除以8 再除以2 ,也是幾兩等於幾斤的轉換.
1/16=0.0625
2/16=0.125     ----> 1/8
3/16=0.1875
4/16=0.25       ----> 2/8 = 1/4
5/16=0.3125
6/16=0.375     ----> 3/8
7/16=0.4375
8/16=0.5        ----> 4/8 = 2/4 = 1/2
9/16=0.5625
10/16=0.625   ----> 5/8
11/16=0.6875
12/16=0.75     ----> 6/8 = 3/4
13/16=0.8125
14/16=0.875   ----> 7/8
15/16=0.9375
16/16=1         ----> 8/8 = 4/4 = 2/2

要熟悉這順序:
0625,1250,1875,2500,
3125,3750,4375,5000,
5625,6250,6875,7500,
8125,8750,9375,10000

各數不斷除以2 的序列:
1, 0.5, 0.25, 0.125, 0.0625,
2, 1, 0.5, 0.25, 0.125,
3, 1.5, 0.75, 0.375, 0.1875,
4, 2, 1, 0.5, 0.25,
5, 2.5, 1.25, 0.625, 0.3125,
6, 3, 1.5, 0.75, 0.375,
7, 3.5, 1.75, 0.875, 0.4375,
8, 4, 2, 1, 0.5,
9, 4.5, 2.25, 1.125, 0.5625,
10, 5, 2.5, 1.25, 0.625,
11, 5.5, 2.75, 1.375, 0.6875,
12, 6, 3, 1.5, 0.75,
13, 6.5, 3.25, 1.625, 0.8125,
14, 7, 3.5, 1.75, 0.875,
15, 7.5, 3.75, 1.875, 0.9375,
16, 8, 4, 2, 1,