WEBVTT
00:00:01.790 --> 00:00:05.250
A small town has 640 residents.
00:00:05.830 --> 00:00:17.640
If seven-eighths of the residents live in houses, and of those residents, only five-sevenths own pets, determine how many of the town’s residents are pet owners.
00:00:19.810 --> 00:00:22.970
In this question, we’re given three bits of information.
00:00:23.380 --> 00:00:27.450
Firstly, the town has 640 residents.
00:00:28.410 --> 00:00:31.380
Seven-eighths of these live in houses.
00:00:32.870 --> 00:00:37.830
And of those that live in houses, five-sevenths own pets.
00:00:38.940 --> 00:00:44.010
Our first step is to calculate the number of residents that live in houses.
00:00:44.630 --> 00:00:48.510
This is equal to seven-eighths of 640.
00:00:49.770 --> 00:00:56.540
In order to calculate the fraction of any amount, we firstly divide by the bottom or denominator.
00:00:57.550 --> 00:01:03.160
We then multiply this answer by the top or numerator of the fraction.
00:01:04.520 --> 00:01:08.860
Our first step here is to divide 640 by eight.
00:01:10.070 --> 00:01:13.890
We can do that by using the short division, bus stop method.
00:01:14.830 --> 00:01:20.490
Eight doesn’t divide into six, so we need to carry the six to the tens column.
00:01:21.960 --> 00:01:29.470
64 divided by eight is equal to eight with no remainder, as eight multiplied by eight is 64.
00:01:31.120 --> 00:01:34.040
Zero multiplied by eight is equal to zero.
00:01:35.120 --> 00:01:39.650
This means that 640 divided by eight equals 80.
00:01:40.840 --> 00:01:45.550
We now need to multiply this answer by our numerator, which was seven.
00:01:47.150 --> 00:01:52.340
From our times tables, eight multiplied by seven is equal to 56.
00:01:53.240 --> 00:01:58.100
This means that 80 multiplied by seven is equal to 560.
00:01:59.270 --> 00:02:07.840
As seven-eighths of 640 is 560, then there are 560 residents that live in houses.
00:02:08.980 --> 00:02:13.890
Our next step is to calculate the number of residents that own pets.
00:02:14.860 --> 00:02:20.140
We were told that five-sevenths of the residents that live in houses own pets.
00:02:20.480 --> 00:02:24.910
Therefore, we need to calculate five-sevenths of 560.
00:02:26.530 --> 00:02:32.870
Once again, we can divide by the denominator and then multiply by the numerator of the fraction.
00:02:34.520 --> 00:02:39.130
We could divide 560 by seven using the bus stop method again.
00:02:40.360 --> 00:02:44.270
However, 56 divided by seven is equal to eight.
00:02:44.630 --> 00:02:48.830
Therefore 560 divided by seven is equal to 80.
00:02:50.370 --> 00:02:54.960
We now need to multiply this answer by our numerator of five.
00:02:56.240 --> 00:02:58.920
Eight multiplied by five is equal to 40.
00:02:59.180 --> 00:03:03.080
Therefore, 80 multiplied by five is equal to 400.
00:03:04.290 --> 00:03:11.410
This means that 400 out of the 640 residents in the small town are pet owners.