1
00:00:00,228 --> 00:00:04,714
Lets see if we can express 16 over 21 as an decimal

2
00:00:04,852 --> 00:00:06,355
Or we can call this sixteen twenty first.

3
00:00:06,370 --> 00:00:09,185
This is also sixteen divided by 21.

4
00:00:09,339 --> 00:00:12,610
So we can literally just divide 21 into 16.

5
00:00:12,718 --> 00:00:14,582
And because 21 is larger than 16,

6
00:00:14,613 --> 00:00:17,301
we're going to get something less than 1.

7
00:00:17,424 --> 00:00:22,113
So let's just literally divide 21 into 16.

8
00:00:22,205 --> 00:00:25,282
And we we're going to have some less than one, so lets add some decimal places here.

9
00:00:25,359 --> 00:00:31,216
We're going to round to the nearest thousandths in case our digits just keep going on and on and on.

10
00:00:31,339 --> 00:00:34,759
And let's start dividing, 21 goes into 1 zero times,

11
00:00:34,759 --> 00:00:36,724
21 goes into 16 zero times.

12
00:00:36,832 --> 00:00:41,727
21 goes into 160, well, 20 would go into 160 8 times,

13
00:00:41,773 --> 00:00:45,859
So let's try 7, lets see if 7 is the right thing.

14
00:00:46,166 --> 00:00:52,524
7 times 1 is 7, 7 times 2 is 14 and then when we subtract,

15
00:00:52,678 --> 00:00:54,529
we should get a remainder less than 21.

16
00:00:54,559 --> 00:00:59,562
If we picked the largest number here that goes into the largest number here,

17
00:00:59,686 --> 00:01:03,651
that if I multiply it by 21 I get close to 160 without going over.

18
00:01:03,682 --> 00:01:07,271
And so if we subtract we do get 13, we do get 13.

19
00:01:07,348 --> 00:01:10,570
So that worked, 13 is less than 21.

20
00:01:10,586 --> 00:01:13,240
And you could just subtract, I did it in my head right there,

21
00:01:13,302 --> 00:01:15,678
but you could re-group, you could say that this is a 10

22
00:01:15,678 --> 00:01:17,369
and then this would be a 5

23
00:01:17,430 --> 00:01:18,755
10 minus 7 is 3.

24
00:01:18,878 --> 00:01:20,105
5 minus 4 is 1,

25
00:01:20,151 --> 00:01:22,107
1 minus 1 is zero.

26
00:01:22,214 --> 00:01:25,953
Now lets bring down a zero

27
00:01:26,122 --> 00:01:30,279
21 goes into 130, so lets see, would 6 work?

28
00:01:30,587 --> 00:01:31,738
It looks like 6 would work

29
00:01:31,845 --> 00:01:34,769
6 times 21 is 126, so that looks like it works.

30
00:01:34,784 --> 00:01:36,665
So lets put a 6 there

31
00:01:36,695 --> 00:01:38,292
6 times 1 is 6

32
00:01:38,338 --> 00:01:42,468
6 times 2 is 120. There's a little bit of an art to this.

33
00:01:42,545 --> 00:01:43,876
Alright, now let's subtract.

34
00:01:44,015 --> 00:01:45,421
Once again, we can regroup,

35
00:01:45,483 --> 00:01:48,290
this would be a 10, we've taken 10 from

36
00:01:48,290 --> 00:01:50,716
essentially this 30, so this becomes a 2

37
00:01:50,808 --> 00:01:53,152
10 minus six is 4

38
00:01:53,352 --> 00:01:54,541
2 minus 2 is zero

39
00:01:54,618 --> 00:01:56,138
1 minus 1 is zero.

40
00:01:56,199 --> 00:02:00,329
Now let's bring down, now lets bring down another zero

41
00:02:00,329 --> 00:02:03,791
21 goes into 40, well, almost 2 times

42
00:02:03,930 --> 00:02:06,116
but not quite, so only 1 time.

43
00:02:06,301 --> 00:02:09,762
1 times 21 is 21, and now lets subtract

44
00:02:09,839 --> 00:02:12,269
This is a 10, this becomes a 3.

45
00:02:12,330 --> 00:02:14,239
10 minus 1 is 9

46
00:02:14,531 --> 00:02:17,885
3 minus 2 is 1 and we're going to have get

47
00:02:17,885 --> 00:02:21,315
this digit because we want to round to the nearest thousand.

48
00:02:21,376 --> 00:02:24,572
So if this is 5 or over we're going to round up

49
00:02:24,633 --> 00:02:28,084
if this is less than 5 we're going to round down.

50
00:02:28,192 --> 00:02:30,152
So let's bring another 0, lets bring another

51
00:02:30,182 --> 00:02:32,974
lets bring another zero down here

52
00:02:33,036 --> 00:02:38,098
and 21 goes into 190, lets see I think 9 will work

53
00:02:38,436 --> 00:02:41,135
Lets try 9, 9 times 1 is 9

54
00:02:41,243 --> 00:02:49,067
9 times 2 is 18, when you subtract 190 minus 189 is 1

55
00:02:49,343 --> 00:02:52,913
And we could keep going on and on but we already have

56
00:02:52,959 --> 00:02:54,925
enough digits to round to the nearest thousand.

57
00:02:55,017 --> 00:02:57,911
This digit right over here is greater than

58
00:02:58,126 --> 00:03:01,387
this is greater than or equal to 5, so we will round up

59
00:03:01,602 --> 00:03:03,957
in the thousandths place.

60
00:03:04,141 --> 00:03:05,808
So if we round to the nearest thousandths,

61
00:03:05,993 --> 00:03:09,370
we can say that this is 0.76

62
00:03:09,523 --> 00:03:14,400
and then this where we're going to round up, 762.