Video Transcript
Fill in the missing value: one-half of an hour plus one-third of an hour plus one-fourth of an hour equals blank minutes.
The first thing we need to think of is how many minutes are in one hour. We know that one hour equals 60 minutes. And we need to use this information to figure out how many minutes are in one-half of an hour, one-third of an hour, and one-fourth of an hour. One-half of an hour would be equal to one-half of 60 minutes. And that means we need to multiply one-half by 60 to find out how many minutes are in half of one hour.
One-half of 60 is equal to 60 over two, and 60 divided by two equals 30. Half of an hour equals 30 minutes, and it’s probable that you’ve already memorized that value. You probably know that half an hour is 30 minutes. But here’s the mathematical way we show that. We can follow the same process for a third of an hour, which is maybe a less common fraction that you don’t think about. When it comes to time, one-third of 60 minutes will be one-third times 60, or 60 divided by three, and that equals 20. A third of an hour in minutes is 20 minutes.
What about a fourth of an hour? Sometimes you might even hear this called a quarter of an hour. Of course, we can multiply one-fourth by 60, but instead let’s think of a clock. If we divide it into fourths and then the minute hand moves from the 12 to the 3, that space is 15 minutes. And mathematically, 60 divided by four does equal 15. For our final answer, we’ll need to add 30 plus 20 plus 15, which is 65. The missing value in this statement is then 65.
