WEBVTT
00:00:01.850 --> 00:00:05.640
One-third of an hour equals what minutes?
00:00:07.760 --> 00:00:11.310
When we tell the time, there are different fractions of the hour that we use.
00:00:12.140 --> 00:00:17.810
For example, we know that half of an hour is worth 30 minutes.
00:00:18.840 --> 00:00:20.210
How do we actually know this though?
00:00:20.210 --> 00:00:23.630
Is this something we’re taught or is there a way to work this out?
00:00:24.410 --> 00:00:27.880
We know that one hour is worth 60 minutes.
00:00:29.450 --> 00:00:37.350
So, for example, to find half of that hour, we need to divide 60 minutes by two, which is where we get the answer 30 from.
00:00:38.230 --> 00:00:47.490
We don’t usually use a third of an hour when telling the time, but let’s use this same method to help us to find the number of minutes in one-third of an hour.
00:00:48.490 --> 00:00:53.020
To find one-third of something, we divide it by three.
00:00:53.540 --> 00:00:57.060
So, what is 60 minutes divided by three?
00:00:58.070 --> 00:01:00.640
Here’s where we can use a known fact to help us.
00:01:01.290 --> 00:01:05.020
Six divided by three equals two.
00:01:06.200 --> 00:01:12.850
And so, six 10s, or 60, divided by three will give us an answer 10 times as large.
00:01:13.060 --> 00:01:14.450
So, the answer’s 20.
00:01:15.370 --> 00:01:18.420
One-third of 60 equals 20.
00:01:19.150 --> 00:01:29.050
And so, one-third of an hour is worth five, 10, 15, 20 minutes.
00:01:30.240 --> 00:01:36.770
Although we don’t use one-third of an hour when telling the time, we can still use our knowledge of fractions to help find the answer.
00:01:37.690 --> 00:01:41.840
To find a third of an hour, we divided 60 by three.
00:01:43.600 --> 00:01:47.800
One-third of an hour equals 20 minutes.