WEBVTT 00:00:00.330 --> 00:00:01.320 - [Instructor] Let's say we wanna figure out 00:00:01.320 --> 00:00:04.060 what eight divided by 4/10 is. 00:00:04.060 --> 00:00:06.250 Pause this video and try to figure it out on your own 00:00:06.250 --> 00:00:08.240 before we do it together. 00:00:08.240 --> 00:00:11.150 All right, now one way to approach this is 00:00:11.150 --> 00:00:13.280 to think about everything in terms of tenths. 00:00:13.280 --> 00:00:15.040 And why tenths, you ask? 00:00:15.040 --> 00:00:19.110 Well, I just described the second number as 4/10. 00:00:19.110 --> 00:00:21.660 So what would eight be in terms of tenths? 00:00:21.660 --> 00:00:24.510 Well, we know that one whole 00:00:24.510 --> 00:00:27.163 is equal to 10/10, 00:00:28.070 --> 00:00:32.063 so eight wholes is going to be equal to 80/10. 00:00:33.370 --> 00:00:34.680 So I could write that down over here. 00:00:34.680 --> 00:00:38.400 Instead of eight, I can write that as 80/10. 00:00:38.400 --> 00:00:41.580 And I'm taking 80/10 and I'm dividing that by, 00:00:41.580 --> 00:00:43.520 divided by 4/10. 00:00:43.520 --> 00:00:46.770 I'm just writing out, 4/10. 00:00:46.770 --> 00:00:48.860 So if I have 80 of something, 00:00:48.860 --> 00:00:52.370 and if I'm diving it into groups of four of that something, 00:00:52.370 --> 00:00:54.660 how many equal groups am I going to have? 00:00:54.660 --> 00:00:57.430 Well, I'm gonna have 80 divided by four groups, 00:00:57.430 --> 00:01:00.390 or 80 divided by four, eight divided by four. 00:01:00.390 --> 00:01:01.540 Actually, let me just write that down. 00:01:01.540 --> 00:01:05.150 This is going to be equal to 80 over four 00:01:05.150 --> 00:01:06.890 or 80 divided by four. 00:01:06.890 --> 00:01:08.800 And eight divided by four is two, 00:01:08.800 --> 00:01:12.500 so 80 divided by four is going to be equal to 20. 00:01:12.500 --> 00:01:16.510 So eight divided by 4/10 is equal to 20. 00:01:16.510 --> 00:01:18.630 Another way that you could think about that is 00:01:18.630 --> 00:01:20.900 to rewrite eight divided by 4/10 00:01:20.900 --> 00:01:25.900 as eight over 4/10. 00:01:26.290 --> 00:01:28.320 Over 4/10. 00:01:28.320 --> 00:01:30.480 And then if you wanted to rewrite this, 00:01:30.480 --> 00:01:32.867 you could say, "Hey, can I multiply the numerator 00:01:32.867 --> 00:01:35.727 "and the denominator by some quantity that'll get rid 00:01:35.727 --> 00:01:37.840 "of the decimal in the denominator?" 00:01:37.840 --> 00:01:40.970 Well, I could multiply the denominator by 10. 00:01:40.970 --> 00:01:42.700 And if I don't wanna change the value of the fraction, 00:01:42.700 --> 00:01:45.240 I have to multiply the numerator by that same amount. 00:01:45.240 --> 00:01:47.180 Well, what does that get us? 00:01:47.180 --> 00:01:49.380 Well, this is going to be equal to, 00:01:49.380 --> 00:01:51.200 in the denominator right over here, 00:01:51.200 --> 00:01:53.180 I'm just going to have a four. 00:01:53.180 --> 00:01:55.190 So we got rid of the decimal. 00:01:55.190 --> 00:01:58.730 In the numerator, I am going to get 80. 00:01:58.730 --> 00:02:02.530 So once again, we get 80 over four, which is equal to 20. 00:02:02.530 --> 00:02:03.610 Let's do another example, 00:02:03.610 --> 00:02:06.460 but in this case we'll deal with hundredths. 00:02:06.460 --> 00:02:09.170 So let's say we want to figure out 00:02:09.170 --> 00:02:12.790 what is 48 00:02:12.790 --> 00:02:16.710 divided by 0.24 00:02:17.870 --> 00:02:20.200 or 24/100? 00:02:20.200 --> 00:02:22.400 Pause this video and try to figure that out. 00:02:23.410 --> 00:02:26.410 All right, well, we can do something very similar. 00:02:26.410 --> 00:02:28.250 This time we're dealing with hundredths, 00:02:28.250 --> 00:02:29.940 so we could try to express everything 00:02:29.940 --> 00:02:31.630 in terms of hundredths. 00:02:31.630 --> 00:02:35.320 So 48 is equal to how many hundredths? 00:02:35.320 --> 00:02:39.733 Well, we know that one is equal to 100/100, 00:02:42.507 --> 00:02:46.450 so 48 is going to be equal 00:02:46.450 --> 00:02:51.450 to 48 times 100/100. 00:02:51.670 --> 00:02:53.600 Maybe I'll just write it like that. 00:02:53.600 --> 00:02:55.417 Or you might be able to say, "Hey, that's 4,800 00:02:55.417 --> 00:02:57.980 "or 4,800/100." 00:02:57.980 --> 00:02:59.750 So let's just, actually, I'll write it that way. 00:02:59.750 --> 00:03:04.750 This is going to be 4,800/100 00:03:07.120 --> 00:03:11.450 divided by, this is 24/100. 00:03:11.450 --> 00:03:13.843 24/100. 00:03:15.500 --> 00:03:17.360 And so what's that going to be? 00:03:17.360 --> 00:03:19.290 Well, same logic as we used up here. 00:03:19.290 --> 00:03:22.400 If I have 4,800 of something or 4,800 of something 00:03:22.400 --> 00:03:24.540 and if I'm dividing it into equal groups 00:03:24.540 --> 00:03:27.100 of 24 of that something, 00:03:27.100 --> 00:03:31.430 well, I'm going to have 4,800 divided by 24 equal groups. 00:03:31.430 --> 00:03:34.210 So this is going to be equal to 4,800 00:03:36.029 --> 00:03:38.160 over 24. 00:03:38.160 --> 00:03:42.970 We could express 4,800 as, of course, 48 times a hundred. 00:03:42.970 --> 00:03:44.810 So this is equal to 48 00:03:44.810 --> 00:03:48.730 times 100 over 24. 00:03:48.730 --> 00:03:51.450 And of course, you could view this as the same thing 00:03:51.450 --> 00:03:55.103 as this is equal to 48 over 24. 00:03:56.070 --> 00:03:59.580 48 over 24, and many of you might have already done it 00:03:59.580 --> 00:04:02.193 in your head, times 100. 00:04:03.130 --> 00:04:05.820 What's 48 divided by 24? 00:04:05.820 --> 00:04:08.290 Well, that is going to be equal to two. 00:04:08.290 --> 00:04:11.340 So two times a hundred is equal to 200. 00:04:11.340 --> 00:04:14.460 So this right over here is equal to 200. 00:04:14.460 --> 00:04:16.300 You can also do it in this type 00:04:16.300 --> 00:04:18.630 or do it similar to the way we did this 00:04:18.630 --> 00:04:22.710 where instead of expressing it out as words, 00:04:22.710 --> 00:04:26.000 you could express it as 48 over 24/100. 00:04:26.000 --> 00:04:27.510 And instead of multiplying the numerator 00:04:27.510 --> 00:04:28.500 and denominator by 10, 00:04:28.500 --> 00:04:30.540 maybe you wanna multiply it by something else 00:04:30.540 --> 00:04:33.640 to get whole numbers in both the numerator and denominator. 00:04:33.640 --> 00:04:35.030 Think about that after this video, 00:04:35.030 --> 00:04:37.053 and try to work it out that way as well.