Video transcript
Let's give ourselvesa little bit of practice with percentages. So let's ask ourselves, whatpercent of-- I don't know, let's say whatpercent of 16 is 4? And I encourage youto pause this video and to try it out yourself. So when you're sayingwhat percent of 16 is 4, percent is another way ofsaying, what fraction of 16 is 4? And we just need to writeit as a percent, as per 100. So if you said what fractionof 16 is 4, you would say, well, look, this isthe same thing as 4/16, which is the same thing as 1/4. But this is saying whatfraction 4 is of 16. You'd say, well, 4 is 1/4 of 16. But that still doesn'tanswer our question. What percent? So in order to writethis as a percent, we literally have to writeit as something over 100. Percent literallymeans "per cent." The word "cent" you knowfrom cents and century. It relates to the number 100. So it's per 100. So you could say,well, this is going to be equal to question markover 100, the part of 100. And there's a bunch of waysthat you could think about this. You could say, well, look,if in the denominator to go from 4 to 100, Ihave to multiply by 25. In the numeratorto go from-- I need to also multiply by 25 in orderto have an equivalent fraction. So I'm also goingto multiply by 25. So 1/4 is the samething as 25/100. And another way of saying 25/100is this is 25 per 100, or 25%. So this is equal to 25%. Now, there's acouple of other ways you could have thought about it. You could have saidwell, 4/16, this is literally 4 divided by 16. Well, let me justdo the division and convert to adecimal, which is very easy to convertto a percentage. So let's try to actually dothis division right over here. So we're going toliterally divide 4 by 16. Now, 16 goes into 4 zero times. 0 times 16 is 0. You subtract, and you get a 4. And we're not satisfiedjust having this remainder. We want to keep adding zeroes toget a decimal answer right over here. So let's put a decimalright over here. We're going intothe tenths place. And let's throw somezeroes right over here. The decimal makes surewe keep track of the fact that we are now in thetenths, and in the hundredths, and in the thousandths placeif we have to go that far. But let's bring another 0 down. 16 goes into 40 two times. 2 times 16 is 32. If you subtract, you get 8. And you could bringdown another 0. And we have 16 goes into 80. Let's see, 16 goesinto 80 five times. 5 times 16 is 80. You subtract, you have noremainder, and you're done. 4/16 is the same thing as 0.25. Now, 0.25 is the same thingas twenty-five hundredths. Or, this is the samething as 25/100, which is the same thing as 25%.
