1 00:00:00,563 --> 00:00:04,071 We are asked to divide 99.061 or 2 00:00:04,071 --> 00:00:08,015 ninety nine and sixty one thousandths by 100. 3 00:00:08,015 --> 00:00:09,393 And there is a few ways to do it 4 00:00:09,393 --> 00:00:11,089 but all I'm going to do in this video is focus on 5 00:00:11,089 --> 00:00:13,123 kind of a faster way to think about it. 6 00:00:13,123 --> 00:00:14,108 And hopefully it will make sense to you. 7 00:00:14,108 --> 00:00:17,120 And that is also the focus of it. That it makes sense to you. 8 00:00:17,120 --> 00:00:19,733 Let us just think about it a little bit. 9 00:00:19,733 --> 00:00:26,867 So 99.061. So if we were to divide this by 10, 10 00:00:26,867 --> 00:00:28,369 just to make the point clear, 11 00:00:28,369 --> 00:00:31,069 if we were to divide this by 10, what would we get? 12 00:00:31,069 --> 00:00:33,646 Well, we would essentially move the decimal place 13 00:00:33,646 --> 00:00:37,093 one spot to the left. And it should make sense 14 00:00:37,093 --> 00:00:38,672 because we have a little over 99. 15 00:00:38,672 --> 00:00:43,006 If you took 99 divided by 10, you should have a little over 9. 16 00:00:43,006 --> 00:00:46,208 So essentially you would move the decimal place 17 00:00:46,208 --> 00:00:48,790 one to the left when you divide by 10. 18 00:00:48,790 --> 00:00:54,740 So this would be equal to 9.9061. 19 00:00:54,740 --> 00:00:58,413 If you were to divide it by 100, 20 00:00:58,413 --> 00:01:00,867 which is actually the focus of this problem, 21 00:01:00,867 --> 00:01:06,114 so if we divide 99.061 divided by 100. 22 00:01:06,114 --> 00:01:08,346 If we move the decimal place once to the left, 23 00:01:08,346 --> 00:01:10,246 we're dividing by 10. 24 00:01:10,246 --> 00:01:12,529 To divide it by 100, we have to divide it by 10 again. 25 00:01:12,529 --> 00:01:16,087 So we move it over twice. So one, two times. 26 00:01:16,102 --> 00:01:21,456 And so now the decimal place is out in front of that first leading 9. 27 00:01:21,456 --> 00:01:25,877 Which also should make sense. 99 is almost 100. 28 00:01:25,877 --> 00:01:29,467 Or a little bit less than 100. So if you divide it by 100 29 00:01:29,467 --> 00:01:32,082 we should be a little bit less than 1. 30 00:01:32,082 --> 00:01:33,920 And so if you move the decimal place 31 00:01:33,920 --> 00:01:35,368 two places over to the left, 32 00:01:35,368 --> 00:01:37,200 because we're really dividing by 10 twice 33 00:01:37,200 --> 00:01:38,669 if you want to think of it that way, 34 00:01:38,685 --> 00:01:42,738 we will get the decimal in front of the 99. 35 00:01:42,738 --> 00:01:46,208 .99061, we should put a 0 out here, 36 00:01:46,208 --> 00:01:48,277 just sometimes it clarifies things. 37 00:01:48,277 --> 00:01:50,254 So then we get this right over here. 38 00:01:50,254 --> 00:01:52,067 Now one way to think about it, 39 00:01:52,067 --> 00:01:53,731 although I do want you to always imagine that 40 00:01:53,731 --> 00:01:55,241 when you move the decimal place over to the left, 41 00:01:55,241 --> 00:01:58,164 you really are dividing by 10 when you move it to the left. 42 00:01:58,164 --> 00:02:01,144 When you move it to the right, you are multiplying by 10. 43 00:02:01,144 --> 00:02:03,167 Sometimes people say, hey look, 44 00:02:03,167 --> 00:02:05,418 you could just count the number of zeros. 45 00:02:05,418 --> 00:02:08,637 And if you are dividing, so over here you are dividing by 100, 46 00:02:08,637 --> 00:02:14,215 100 has two zeros, so when we're dividing by it, 47 00:02:14,215 --> 00:02:18,005 so we can move our decimal two spaces to the left. 48 00:02:18,005 --> 00:02:20,179 That's alright to do that, if you know 49 00:02:20,179 --> 00:02:21,773 especially if it's kind of a fast way to do it. 50 00:02:21,773 --> 00:02:24,382 If this had 20 zeros, you would have needed to say, 51 00:02:24,382 --> 00:02:26,615 ok, let us move the decimal 20 spaces to the left. 52 00:02:26,615 --> 00:02:29,705 But I really want you to think about why that's working. 53 00:02:29,705 --> 00:02:31,450 Why that makes sense? 54 00:02:31,450 --> 00:02:34,702 Why it's giving you a number that seems to be 55 00:02:34,702 --> 00:02:37,085 in the right kind of size number. 56 00:02:37,085 --> 00:02:38,884 That this is why it makes sense that 57 00:02:38,884 --> 00:02:40,559 if you take something that's almost 100 58 00:02:40,559 --> 00:02:44,995 and divide it by 100, you'll get something that's almost 1. 59 00:02:44,995 --> 00:02:47,843 And that part, frankly, is just a really good reality check 60 00:02:47,843 --> 00:02:50,260 to make sure you're going in the right direction with the decimal. 61 00:02:50,260 --> 00:02:53,338 Because if you were to try this five or ten years from now, 62 00:02:53,338 --> 00:02:56,393 maybe your memory of the rule 63 00:02:56,393 --> 00:02:58,309 or whatever you want to call it for doing it, 64 00:02:58,309 --> 00:03:00,163 you're like, hey, wait. Do I move the decimal 65 00:03:00,163 --> 00:03:01,502 to the left or the right? 66 00:03:01,502 --> 00:03:03,033 It's really good to do that reality check 67 00:03:03,033 --> 00:03:04,902 to say, ok, look. If I'm dividing by 100, 68 00:03:04,902 --> 00:03:07,131 I should be getting a smaller value. 69 00:03:07,131 --> 00:03:09,092 And that moving the decimal to the left 70 00:03:09,092 --> 00:03:10,561 gives me that smaller value. 71 00:03:10,561 --> 00:03:12,984 If I was multiplying by 100, I should get a larger value. 72 00:03:12,984 --> 00:03:15,269 And moving the decimal to the right 73 00:03:15,269 --> 00:03:17,815 would give you that larger value.