9:59:59.000,9:59:59.000
1+4=5 最高位是1 希望大家能看到

9:59:59.000,9:59:59.000
1+9=10

9:59:59.000,9:59:59.000
10+4=14 进1

9:59:59.000,9:59:59.000
12+1=13

9:59:59.000,9:59:59.000
150462

9:59:59.000,9:59:59.000
18+2=20 进2

9:59:59.000,9:59:59.000
4×2=8 8+1

9:59:59.000,9:59:59.000
4×3=12

9:59:59.000,9:59:59.000
4×4--

9:59:59.000,9:59:59.000
4×4=16 进1

9:59:59.000,9:59:59.000
4就乘完了

9:59:59.000,9:59:59.000
6×2=12 12+2=14

9:59:59.000,9:59:59.000
6×3=18

9:59:59.000,9:59:59.000
6×4=24 进2

9:59:59.000,9:59:59.000
下面是6 因为是600

9:59:59.000,9:59:59.000
个位是2 十位是6 百位7+3=10

9:59:59.000,9:59:59.000
代表的是40 在这写个0

9:59:59.000,9:59:59.000
做等级四的习题了！

9:59:59.000,9:59:59.000
先把上边的进位都划掉

9:59:59.000,9:59:59.000
因为4在十位上

9:59:59.000,9:59:59.000
大家现在可以

9:59:59.000,9:59:59.000
希望没有写到屏幕以外吧

9:59:59.000,9:59:59.000
应该是没问题

9:59:59.000,9:59:59.000
得9

9:59:59.000,9:59:59.000
我把自己弄糊涂了

9:59:59.000,9:59:59.000
我经常忘了划掉这些

9:59:59.000,9:59:59.000
所以填两个0

9:59:59.000,9:59:59.000
把之前的进位都划掉

9:59:59.000,9:59:59.000
接下来乘4 或者说40

9:59:59.000,9:59:59.000
然后就像乘6一样来运算

9:59:59.000,9:59:59.000
现在都加起来

9:59:59.000,9:59:59.000
说40也行 看你怎么看了

9:59:59.000,9:59:59.000
进1

9:59:59.000,9:59:59.000
那么我的答案是

0:00:01.290,0:00:02.870
下面来做等级四的乘法运算

0:00:02.870,0:00:04.892
来看一些例题

0:00:04.892,0:00:10.718
用235乘以--

0:00:10.718,0:00:14.330
用两种不同颜色来表示

0:00:14.330,0:00:21.690
换颜色的时候大家可能要稍微等一下

0:00:21.690,0:00:23.498
235乘以47

0:00:23.498,0:00:26.960
做等级四的题目

0:00:26.960,0:00:31.060
就跟做等级三的方法是一样的

0:00:31.070,0:00:36.165
一开始也是用这个7

0:00:36.165,0:00:44.604
乘以235

0:00:44.604,0:00:49.750
7×5=35 进3

0:00:49.780,0:00:51.030
7×3=21

0:00:51.040,0:00:52.560
加上之前的进位3 得24 进2

0:00:52.570,0:00:54.390
7×2=14

0:00:54.390,0:00:58.240
再加上进位2

0:00:58.250,0:01:02.187
得16

0:01:02.187,0:01:04.044
7就乘完了

0:01:04.044,0:01:06.490
然后要乘这个4

0:01:06.500,0:01:09.310
但4是在十位上

0:01:09.310,0:01:14.903
所以要在下边加一个0

0:01:14.903,0:01:17.665
大家可以这么看

0:01:17.665,0:01:24.180
乘235的

0:01:24.180,0:01:29.800
不是4 而是40

0:01:29.810,0:01:32.000
所以要填一个0

0:01:32.010,0:01:40.570
但是在写了0以后

0:01:40.570,0:01:43.670
就可以看成是乘4来运算了

0:01:43.680,0:01:46.220
4×5=20 进2

0:01:46.230,0:01:48.150
把上一步的进位划掉

0:01:48.150,0:01:56.882
4×3=12

0:01:56.882,0:02:00.559
加上进上来的2

0:02:00.559,0:02:06.085
得14 进1

0:02:06.085,0:02:08.082
4×2=8

0:02:08.082,0:02:10.791
加上进位1

0:02:10.791,0:02:13.110
得9

0:02:13.120,0:02:15.165
现在把两个乘积加起来

0:02:15.165,0:02:15.950
5+0=5

0:02:15.960,0:02:19.869
4+0=4

0:02:19.869,0:02:22.646
6+4=10 进1

0:02:22.650,0:02:23.588
1+1+9 得11

0:02:23.588,0:02:26.714
所以结果是11045

0:02:26.714,0:02:32.070
再做一道

0:02:32.080,0:02:40.090
用873乘以--

0:02:40.090,0:02:44.400
我是在临时凑数

0:02:44.410,0:02:46.470
所以比较慢--

0:02:46.470,0:02:47.570
873乘以--找个大数--

0:02:47.580,0:02:49.410
9--个位十位我用不同的颜色写

0:02:49.410,0:02:53.830
这样大家就能更好理解

0:02:53.840,0:02:56.006
我说的是什么意思了

0:02:56.006,0:02:59.310
乘以97

0:02:59.310,0:03:02.028
刚用过7了

0:03:02.028,0:03:03.525
就98吧

0:03:03.525,0:03:06.710
就跟之前的步骤一样 先看个位

0:03:06.710,0:03:12.930
也就是8

0:03:12.940,0:03:20.805
8×873

0:03:20.805,0:03:22.336
8×3=24

0:03:22.352,0:03:25.480
进2

0:03:25.490,0:03:28.030
8×7=56

0:03:28.030,0:03:29.710
56+2=58

0:03:29.710,0:03:36.234
进5

0:03:36.234,0:03:42.160
8×8=64

0:03:42.160,0:03:45.183
加上刚进的5

0:03:45.183,0:03:48.012
就是69

0:03:48.012,0:03:50.870
8就乘完了

0:03:50.880,0:03:51.900
接下来乘9

0:03:51.900,0:03:54.650
或者说

0:03:54.660,0:03:55.792
是873乘以90

0:03:55.792,0:03:58.220
但是乘以90就是

0:03:58.220,0:04:00.595
乘以9--

0:04:00.595,0:04:03.770
后边再加个0

0:04:03.770,0:04:10.971
所以在这写个0

0:04:10.971,0:04:13.848
然后9×3=27 进2

0:04:13.848,0:04:23.148
忘了要先划掉这些进位了

0:04:23.148,0:04:26.010
把之前写的都划掉

0:04:26.020,0:04:28.940
9×3=27

0:04:28.940,0:04:32.300
进2

0:04:32.310,0:04:36.560
9×7=63

0:04:36.560,0:04:38.610
加上进位2 是65

0:04:38.620,0:04:41.178
进6

0:04:41.178,0:04:43.720
9×8=72

0:04:43.730,0:04:45.539
加上进位6

0:04:45.539,0:04:46.950
是78

0:04:46.950,0:04:48.430
然后再做加法

0:04:48.430,0:04:50.860
个位是4 8+7=15 进1

0:04:50.870,0:04:54.338
1+9+5=15 进1

0:04:54.338,0:04:56.430
1+6+8还是15 进1

0:04:56.430,0:04:58.564
1+7=8

0:04:58.564,0:05:03.018
手边又没有计算器--

0:05:03.018,0:05:04.386
如果我没算错的话--

0:05:04.386,0:05:06.134
如果没有粗心计算错误

0:05:06.134,0:05:08.393
那么答案是85554

0:05:08.393,0:05:12.135
再做一道

0:05:12.135,0:05:19.120
这道题能清楚阐释我要说的内容

0:05:19.120,0:05:23.670
下一道题

0:05:23.680,0:05:25.468
差不多是等级五的内容

0:05:25.468,0:05:26.500
因为我要写的是

0:05:26.510,0:05:29.354
两个三位数相乘

0:05:29.404,0:05:32.874
但其实道理是一样的

0:05:32.874,0:05:34.355
希望大家能够发现运算的规律

0:05:34.355,0:05:37.177
那么 234乘以--

0:05:37.177,0:05:41.220
现在要用三种颜色来写了

0:05:41.220,0:05:47.490
643

0:05:47.500,0:05:52.700
首先来算个位的3

0:05:52.700,0:05:55.460
8×234

0:05:55.470,0:05:59.670
3×4=12 进1

0:05:59.680,0:06:02.258
3×3=9 9+1

0:06:02.258,0:06:04.228
得10 进1

0:06:04.228,0:06:05.469
3×2=6 6+1

0:06:05.469,0:06:07.370
得7

0:06:07.378,0:06:09.601
个位就做完了

0:06:09.601,0:06:13.690
我觉得哪里做错了 来看一下

0:06:13.690,0:06:16.958
3×4=12--