Learn about Percent and decimals Video

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Learn about Percent and decimals

Learn about Percent and decimals Let’s get started and learn how to convert percentages to decimals and if we have time maybe we’ll also learn how to convert decimals into percentages. So let’s get started with what I think is probably you all ready know how to do. If I said I have 50% and I want to turn that into a decimal. Well, you probably all ready have a sense of what a decimal represents 50%. If I told you we’re having a sale on 50% off you know that’s roughly half off or another way with how do you say half as a decimal? Well that’s the same thing as 0.5. So you might have known that in your head but is there a system for being able to convert this 50% to.05? Well it turns out, it’s pretty straightforward. All you do is you say whatever percentage it is that’s the same thing as the number over a hundred. And 50/100 is the same thing as 5/10 or 0.5. Now even a simpler way of converting percentage to decimals and I think you’re going to realize converting a percentage to a decimal or the other way around you can pretty much do in your head is let’s say 50 and I’m just going to add one decimal of accuracy here just to show you a point, 50%. If I want to convert that 50% into a decimal all I do is I get rid of the percent sign and I take the decimal point and I move it over two spaces to the left. So I say 1 2, so this is where the new decimal is. So this equals 0.500. So 50% = 0.500 and of course this last two zeroes really don’t mean anything for our purposes so we’ll get rid of them so that’s the same thing as 0.5 or just .5. So you're probably saying, well sure that looks easy but what if the problem gets a little harder? 50% like I’m doing in my head. So let’s try some, I would say slightly harder problems. If I were to tell you that let’s say 16.32%. Well let’s just do it the way I just showed you. We can get 16.32%, so if we get rid of the percent sign scratch it out. We just have to move the decimal over two spaces to the left. So 1 2, this is the new place for the decimal that that will goes away so it’s .1632 = 16.32%. I think you might be getting the idea now. Let me do another one in green. This one actually confuses a lot of people. Let’s say I had 0.25%, so the important thing to remember is 00.25%. Well just what the system I just showed you. You get rid of the percent sign and you move the decimal over 1 2 spaces. So that equals .0025. So .25% = .0025 and you could put leading zero here if you want. Some people they actually, I should probably tell you to always do that because it makes it easier to read. So .25% = .0025 and I want just contrast that with 25%. At 25% what do you think that equals? Well you do the same thing that we’ve been doing. You get rid of the percent sign and you move the decimal space, in this case actually I'm going to leave that then I’ll just rewrite here 25% and you're probably saying where is the decimal in this? Well the decimal is after the number because that 25% is same thing as 25.0%. So if we get rid of the percent sign we move the decimal over two spaces to the left and that equals .25 while .25% = .0025 and I want you to maybe sit and think about how small of a number point 25% is. Let’s do a couple of more, maybe we’ll convert going to other direction. If I were to say, let’s say I have the decimal point 01 and I want it to convert that to a percent? Well here, we just do it the opposite. We could look at it 2 ways, we could say well whatever number this is we multiply it by a 100 and add a percent sign. So if you say .01 times 100 and then will add a percent sign so .01 times a 100 well that just one right. You could do the math, the other percent that equals 1%. Or even in easier way when we go from a percent to a decimal we move the decimal place over two to the left. So we go from a decimal to a percent we’ll do the opposite. We move the decimal to the right. So if we do that, let me just rewrite it .01, if you just go 1 2 the new decimal places here. So I mean if I get rid of that decimal that’s 01.00 whatever, this obviously this leading zero means nothing so that’s the same thing as 1.00 which is the same thing as 1. And does it make sense that moving the decimal space to the right that’s really just the same thing as multiplying it by 100, right? If I multiply by something by 10 it’s like moving the decimal space one to the right. If I divide something by 10 it’s like moving the decimal space one to the left. Let’s do a couple of more while I have time. Let’s say I had 1.25 and I want to convert that to a percent. Well, the easiest way is just to take—1.25, take the decimal point and move it to the right. So that equals and then I’ll add a percent so that equals 125%. And if you think about it the way people talk about percentage it makes sense. If I told you that I’m going to pay 1.25 times the price of something that makes sense and that’s also I’m going to pay a 125% of the price. Or if it doesn’t make sense hopefully if you do this problem enough we will start to make sense. Let’s do a couple of more and you can go back and pause this if you think I’m going to fast which I might be doing. If I were to say, .003 and I want to write this as a percent. Well once again we can move the decimal space two to the right so 1 2 and now I guess to multiplying it by a 100. So if we multiply the decimal two to the right, we get 00.3 and then we add the percent, at least this first thing or zero doesn’t mean I think so that’s the same thing as your 0.3% So the important thing to realize is when you’re converting from a percent to a decimal or decimal to a percent you really just moving where that decimal point is and if you run out of spaces you just have to add or get rid of zeroes accordingly and the important thing to always have in your mind is when I convert from a decimal to a percent the number in front of the percent sign is going to get bigger and when I go from a percent sign to a decimal I’m going to get a smaller number. Like if I say 25% that’s the same thing as .25 so this is percent and this is a decimal. So I went from a bigger number 25 to a smaller number .25, 25% = .25. Similarly if I had a decimal, let’s say .1 when I convert to a percentage is going to be a larger percentage. So .1 is the same thing as 10% and how do I do that again? Well I said .1, add extra zero because I have to move the decimal space over to the right twice. I go 1 2 and I get a 10%. Hopefully that answers all your questions for now, have fun.

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Learn about Percent and decimals

Let’s get started and learn how to convert percentages to decimals and if we have time maybe we’ll also learn how to convert decimals into percentages. So let’s get started with what I think is probably you all ready know how to do. If I said I have 50% and I want to turn that into a decimal. Well, you probably all ready have a sense of what a decimal represents 50%. If I told you we’re having a sale on 50% off you know that’s roughly half off or another way with how do you say half as a decimal? Well that’s the same thing as 0.5. So you might have known that in your head but is there a system for being able to convert this 50% to.05?

Well it turns out, it’s pretty straightforward. All you do is you say whatever percentage it is that’s the same thing as the number over a hundred. And 50/100 is the same thing as 5/10 or 0.5. Now even a simpler way of converting percentage to decimals and I think you’re going to realize converting a percentage to a decimal or the other way around you can pretty much do in your head is let’s say 50 and I’m just going to add one decimal of accuracy here just to show you a point, 50%. If I want to convert that 50% into a decimal all I do is I get rid of the percent sign and I take the decimal point and I move it over two spaces to the left. So I say 1 2, so this is where the new decimal is. So this equals 0.500. So 50% = 0.500 and of course this last two zeroes really don’t mean anything for our purposes so we’ll get rid of them so that’s the same thing as 0.5 or just .5.

So you're probably saying, well sure that looks easy but what if the problem gets a little harder? 50% like I’m doing in my head. So let’s try some, I would say slightly harder problems. If I were to tell you that let’s say 16.32%. Well let’s just do it the way I just showed you. We can get 16.32%, so if we get rid of the percent sign scratch it out. We just have to move the decimal over two spaces to the left. So 1 2, this is the new place for the decimal that that will goes away so it’s .1632 = 16.32%. I think you might be getting the idea now. Let me do another one in green. This one actually confuses a lot of people. Let’s say I had 0.25%, so the important thing to remember is 00.25%. Well just what the system I just showed you. You get rid of the percent sign and you move the decimal over 1 2 spaces. So that equals .0025. So .25% = .0025 and you could put leading zero here if you want. Some people they actually, I should probably tell you to always do that because it makes it easier to read.

So .25% = .0025 and I want just contrast that with 25%. At 25% what do you think that equals? Well you do the same thing that we’ve been doing. You get rid of the percent sign and you move the decimal space, in this case actually I'm going to leave that then I’ll just rewrite here 25% and you're probably saying where is the decimal in this? Well the decimal is after the number because that 25% is same thing as 25.0%. So if we get rid of the percent sign we move the decimal over two spaces to the left and that equals .25 while .25% = .0025 and I want you to maybe sit and think about how small of a number point 25% is. Let’s do a couple of more, maybe we’ll convert going to other direction.

If I were to say, let’s say I have the decimal point 01 and I want it to convert that to a percent? Well here, we just do it the opposite. We could look at it 2 ways, we could say well whatever number this is we multiply it by a 100 and add a percent sign.

So if you say .01 times 100 and then will add a percent sign so .01 times a 100 well that just one right. You could do the math, the other percent that equals 1%. Or even in easier way when we go from a percent to a decimal we move the decimal place over two to the left. So we go from a decimal to a percent we’ll do the opposite. We move the decimal to the right. So if we do that, let me just rewrite it .01, if you just go 1 2 the new decimal places here. So I mean if I get rid of that decimal that’s 01.00 whatever, this obviously this leading zero means nothing so that’s the same thing as 1.00 which is the same thing as 1. And does it make sense that moving the decimal space to the right that’s really just the same thing as multiplying it by 100, right? If I multiply by something by 10 it’s like moving the decimal space one to the right. If I divide something by 10 it’s like moving the decimal space one to the left. Let’s do a couple of more while I have time.

Let’s say I had 1.25 and I want to convert that to a percent. Well, the easiest way is just to take—1.25, take the decimal point and move it to the right. So that equals and then I’ll add a percent so that equals 125%. And if you think about it the way people talk about percentage it makes sense. If I told you that I’m going to pay 1.25 times the price of something that makes sense and that’s also I’m going to pay a 125% of the price. Or if it doesn’t make sense hopefully if you do this problem enough we will start to make sense. Let’s do a couple of more and you can go back and pause this if you think I’m going to fast which I might be doing.

If I were to say, .003 and I want to write this as a percent. Well once again we can move the decimal space two to the right so 1 2 and now I guess to multiplying it by a 100. So if we multiply the decimal two to the right, we get 00.3 and then we add the percent, at least this first thing or zero doesn’t mean I think so that’s the same thing as your 0.3%

So the important thing to realize is when you’re converting from a percent to a decimal or decimal to a percent you really just moving where that decimal point is and if you run out of spaces you just have to add or get rid of zeroes accordingly and the important thing to always have in your mind is when I convert from a decimal to a percent the number in front of the percent sign is going to get bigger and when I go from a percent sign to a decimal I’m going to get a smaller number. Like if I say 25% that’s the same thing as .25 so this is percent and this is a decimal. So I went from a bigger number 25 to a smaller number .25, 25% = .25. Similarly if I had a decimal, let’s say .1 when I convert to a percentage is going to be a larger percentage. So .1 is the same thing as 10% and how do I do that again? Well I said .1, add extra zero because I have to move the decimal space over to the right twice. I go 1 2 and I get a 10%. Hopefully that answers all your questions for now, have fun.

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