WEBVTT
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Hours and Minutes
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In this video, we will learn how to identify the number of minutes in an hour and how to convert between hours and minutes using models.
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To help us convert between minutes and hours, we need to know how many minutes there are in one hour.
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Let’s count them.
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Each number on the clock represents five minutes.
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Let’s count around the clock in fives.
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Five, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60.
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There are 60 minutes in one hour.
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If one hour equals 60 minutes, how many minutes are there in half an hour?
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What is half of 60?
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We know that half of six is three.
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So half of 60 is 30.
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How many minutes are there in a quarter of an hour?
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We know that half an hour is 30 minutes and there are two-quarters in a half hour.
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So we need to halve 30.
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There are 15 minutes in a quarter hour.
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There are four quarter hours in an hour.
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Each quarter of an hour is worth 15 minutes.
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If quarter of an hour is worth 15 minutes, then three-quarters of an hour will be worth 45 minutes and one-third of an hour is worth 20 minutes.
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If there are 60 minutes in one hour, how many minutes would that be in two hours?
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What is 60 plus 60 or double 60?
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We know that double six is 12; double 60 is 120.
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If there are 60 minutes in one hour, there are 120 minutes in two hours.
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We’ve learned that there are 60 minutes in one hour.
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Let’s use this fact to help us answer some questions, where we’re asked to convert from minutes to hours or hours to minutes.
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One hour and 30 minutes is what minutes.
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Think: How many minutes are in one hour?
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In this question, we’re shown a part–whole model.
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The whole amount is one hour and 30 minutes.
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We know that the first part is one hour and the second part is 30 minutes.
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In this question, we have to work out how many minutes there are in one hour and 30 minutes.
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We’re only given one of the parts in the part–whole model, the 30 minutes.
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To work out how many minutes are in the other part, we need to think about how many minutes there are in an hour.
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There are 60 minutes in one hour.
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Five, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60.
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Now, what we need to do is add together the two parts, 60 and 30.
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We know that six plus three is nine and six 10s plus three 10s is nine 10s.
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Nine 10s are 90.
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60 plus 30 is 90.
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One hour and 30 minutes is 90 minutes.
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65 minutes is one hour and what minutes.
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Think: How many minutes are in one hour?
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We’re shown a part–whole model.
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We know the whole amount is 65 minutes.
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We know that one of the parts is an hour.
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And we need to work out what the second part is worth.
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We’re told to think about how many minutes there are in one hour.
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There are 60 minutes in one hour.
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Now, we can find the missing part.
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It’s the difference between 60 and 65.
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In other words, we need to subtract 60 from 65.
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Five ones take away no ones leaves us with five ones.
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And six take away six is nothing.
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So 65 take away 60 equals five.
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65 minutes is one hour and five minutes.
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60 plus five makes 65.
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The missing amount is five minutes.
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We know that one hour is 60 minutes.
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So 65 minutes is one hour and five minutes.
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Fill in the blank: Two hours and 10 minutes equals what minutes.
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In this question, we have to work out how many minutes there are in two hours and 10 minutes.
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We could use a part–whole model.
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We know the whole amount is two hours, 10 minutes.
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We could break this amount apart into two hours and 10 minutes.
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We know that this part is worth 10 minutes.
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How many minutes are there in two hours?
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So if one hour is 60 minutes, two hours is double 60.
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We know that six plus six is 12, so 60 plus 60 is 120.
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Now, we just need to add together the two parts.
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What is 120 plus 10?
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It’s 130.
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Two hours and 10 minutes equals 130 minutes.
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What is two and a half hours in minutes?
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We could use a bar model to help us think about this problem.
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The whole amount is two and a half hours.
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Each of these parts is an hour, so there were two hours.
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And this part represents half an hour.
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We know there are 60 minutes in one hour.
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So to find the number of minutes in two hours, we need to double 60.
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Double six is 12; double 60 is 120.
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And we know that half of 60 is 30.
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So to find the total number of minutes in two and a half hours, we need to add together 120 and 30.
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Two and a half hours in minutes is 150 minutes.
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70 minutes is one hour and 10 minutes.
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80 minutes is one hour and what minutes.
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We know that one hour is worth 60 minutes.
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So 70 minutes is 60 plus 10 or one hour and 10 minutes.
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If 60 minutes is worth an hour, then 80 minutes can be partitioned into one hour or 60 minutes and 20 minutes.
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We know that 60 plus 20 equals 80.
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If 70 minutes is one hour and 10 minutes, 80 minutes is one hour and 20 minutes.
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The missing number is 20.
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What have we learned in this video?
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We’ve learned how to identify the number of minutes in an hour and how to convert between hours and minutes using bar models and part–whole models.