WEBVTT
00:00:01.320 --> 00:00:08.840
If Max started his homework at 5:20 am and it took him 50 minutes to complete it, when did he finish?
00:00:10.490 --> 00:00:14.110
Max began doing his homework at 5:20 am.
00:00:15.070 --> 00:00:18.000
5:20 Looks like this on a clock face.
00:00:19.070 --> 00:00:22.790
We’re told that it took Max 50 minutes to complete his homework.
00:00:23.050 --> 00:00:25.580
And we need to calculate the time that he finished.
00:00:26.820 --> 00:00:31.820
50 minutes is going to take us into the next hour, past six o’clock.
00:00:32.480 --> 00:00:38.970
So, we can find the answer by counting to six o’clock and then adding on the rest of the minutes that we have left.
00:00:39.630 --> 00:00:42.810
So, in effect, what we’re doing is partitioning 50.
00:00:43.370 --> 00:00:47.540
The first thing we can do is to count on until we get to six o’clock.
00:00:48.370 --> 00:00:50.820
We know there are 60 minutes in an hour.
00:00:51.250 --> 00:00:59.900
And so, if we’re already at the time of 5:20, we only have to add another 40 minutes to get to six o’clock.
00:01:03.600 --> 00:01:19.500
To prove this is true, we can count in fives around the clock face, five, 10, 15, 20, 25, 30, 35, 40.
00:01:20.140 --> 00:01:23.370
40 minutes will take Max to six o’clock.
00:01:23.760 --> 00:01:27.190
So, the first part of 50 that we’ve added is 40.
00:01:27.970 --> 00:01:29.220
What’s the second part?
00:01:29.720 --> 00:01:33.980
We’ve got another 10 minutes to add to make 50 minutes.
00:01:34.460 --> 00:01:41.850
If we start at 6 am and add 10 minutes, the time becomes 6:10 am.
00:01:43.110 --> 00:01:48.780
Again, we can count in fives on the clock face, five, 10.
00:01:49.600 --> 00:01:55.030
We found the answer by counting on 40 minutes and then 10 minutes.
00:01:55.540 --> 00:01:59.920
The reason we did this is because 40 minutes took us to six o’clock am.
00:02:00.740 --> 00:02:03.560
We could then add the remainder very quickly.
00:02:04.310 --> 00:02:08.270
Six o’clock plus 10 minutes is 10 past six.
00:02:09.560 --> 00:02:18.080
If Max started his homework at 5:20 am, and it took him 50 minutes to complete it, he finished at 6:10 am.