1
00:00:00,040 --> 00:00:05,600
上集影片中我們做了99.061除以100

2
00:00:05,600 --> 00:00:06,830
是手算的

3
00:00:06,830 --> 00:00:08,570
用的長除法

4
00:00:08,570 --> 00:00:10,870
這集影片我要告訴大家

5
00:00:10,870 --> 00:00:13,970
除以10時的一個運算技巧

6
00:00:13,970 --> 00:00:21,690
99.061如果是乘以10的乘方

7
00:00:21,690 --> 00:00:23,280
原數會變大

8
00:00:23,280 --> 00:00:25,110
每次乘以10

9
00:00:25,110 --> 00:00:29,350
小數點要右移一位

10
00:00:29,350 --> 00:00:36,000
那麽99.061乘以10

11
00:00:36,000 --> 00:00:40,870
就等於990.61

12
00:00:40,870 --> 00:00:44,280
注意 小數點正好是向右移了一位

13
00:00:44,280 --> 00:00:47,560
如果--我隨便換個顏色--

14
00:00:47,560 --> 00:00:51,940
99.061除以10

15
00:00:51,940 --> 00:00:54,800
小數點就要向相反方向移動

16
00:00:54,800 --> 00:01:00,090
就會是9.9061

17
00:01:00,090 --> 00:01:04,070
除以100 就是除以10除了兩次

18
00:01:04,070 --> 00:01:06,310
向左移兩位

19
00:01:06,310 --> 00:01:16,570
如果是99.061除以100

20
00:01:16,570 --> 00:01:17,830
我這麽寫

21
00:01:17,830 --> 00:01:19,050
我已經寫出來了

22
00:01:19,050 --> 00:01:20,980
如果是除以100

23
00:01:20,980 --> 00:01:25,770
向左移一位是除以10

24
00:01:25,770 --> 00:01:27,400
再移一位

25
00:01:27,400 --> 00:01:30,810
又除以10

26
00:01:30,810 --> 00:01:41,600
那99.061除以100等於0.99061

27
00:01:41,600 --> 00:01:44,670
小數點左移兩位

28
00:01:44,670 --> 00:01:46,590
小數點前邊要添0

29
00:01:46,590 --> 00:01:49,620
讀起來更方便