PORCENTAGEM \Prof.Gis/ MATEMÁTICA BÁSICA

Hi guys, you won't believe I found the game I wanted so much with a twenty percent discount! But how come I don't exchange it at twenty percent off? So be sure to watch Gis's class and I'll explain percentages, shall we?

So welcome to another class on Gis' channel, take the opportunity to subscribe to the channel if you're not already subscribed and give Gis a thumbs up, okay? So guys, I was walking around the mall and I saw the game I wanted with twenty percent off, but the game I wanted cost 300 reais, so what do I have to do now I have to calculate how much twenty per cent is? cent of 300 reais so I can know how much discount there will be on the game and then can you help me?

How do I have to do? For those of you who attended the class where I explained fractions and percentages, right, you understood the entire representation of a percentage, it can be written in the form of a fraction with a denominator of 100, didn't you see Gis's class? Did not see?

So go back and watch this class, okay? But now guys, I have this representation of 20%, how am I going to write this here in the form of a fraction, so twenty percent is the same thing as me writing 20/100 parts, isn't that right? because percentage is a total divided into 100 divided into 100 and I got 20, so these two representations they are referring to the same thing okay percentage now guys so instead of writing like this I'm going to write using a fraction which is easier for us Calculating is ok?

So it's 20/100 of 300, 300 reais so I'll go for 300 Ok? So how should you carry out this calculation? The first thing to do is take here, take 300 reais, which is the total, which is the total price of the game, and divide it into 100 parts, right, because the percentage is related to the division of 100 parts, So you're going to take 300 reais and you're going to divide it into 100 parts, do the math so you don't forget how I did it, okay, the 300 reais divided into 100 parts will be three, okay, so what does that mean, what did I get 300 reais?

I divided it into 100 parts, each part was 3, so now how many parts am I going to take, it's just one part, no, I didn't take 20, I have 20 here so I have to take this three and I have to make this 3 x 20 because I'm working with 20%, with 20 parts, so here it will be zero and it will be six but I already found the answer so does that mean that twenty percent of 300 is the same thing as 60? That's right guys, if I calculate twenty percent of 300, we'll find 60, okay, so we can write this representation here, 20/100 of 300 and it's equal to 60, okay? so what is this 60?

It's the game's discount , oh, how wonderful, 60 reais off, so if my game cost 300 reais, I'm going to discount 60 reais, how much am I going to pay for the game? 240 very well people just for us is to symbolize so where can I use percentage, you see? And this thing is real, it's not a lie, I 'm not making it up, I really bought this game with everything here at a discount, right?

Now you're going to have to help me, because I collect Pokémon cards right and I was doing the math and I saw that I have 200 cards in total, but of those 200 cards, twelve percent of them are repeated, and then how am I going to find out? Now what is the total number of repeated cards in my collection? Shall we help Gis?

So you already know that this representation here of twelve percent can also be written in the form of a decimal fraction which will be 12/100 which is 12 hundredths, right? So I'm going to calculate 12% of 200 people, I'm doing it here, I think it's the simplest way possible, okay? Now, if you have any other skills, you know how to do it another way, you can also share it here in the comment with Gis, how you calculate percentage, that's also good because I looked for the simplest way here for you to understand, right?

So let's go so I have to get my total cards which is 200 I'm going to divide this total into 100 groups yes 100 parts okay so we're going to divide 200 which is the total number of cards I have by 100 right so what do you mean? that divided 200 by 100 will be two, right, it will be two here with the remainder zero, Ok? so what does it mean that I took 200 and divided them into 100 groups, which means that each little group of mine each little group, let's pretend that I divided it into 100 little groups, they will only represent a few, here, each little group of mine has two cards, o each little group because the result of the division, but now I need to get so how many parts?

I need to get 12 parts. In other words, I need to get 12 of these groups, so what calculation do I do now to get 12 of these groups? just take 12 and make 12 x 2 or make 2 x 12, it will be the same thing, right?

This operation is commutative, and doing it here, I'm going to erase it, right, 12 times 2, 2 times 2, 4 times 12 are 24, so either tell people that when I calculate 12/100 which can be represented in this form of a fraction of 200 what am I going to get then twelve percent of 200 = 24 and then 24 are what? It's the total number of stickers that I have repeated, it's not a sticker, it's cards, right people, so here in my collection of 200, 24 stickers, it's cards, every time Gis says sticker, right, that the 24 cards here are repeated Then I can find someone to exchange it, right? Let's do more examples now, shall we?

Now we're going to calculate the following, look, here with me I have a distance of 380 km to a city that I'm going to, okay, but I'm not going by car, I'm going by bike, that's right by bike, I'm going to spend a lot of time, right? But having a rule for me to go by bike I only have to travel fifteen percent each day so let's help Gis calculate now how much is so fifteen percent of 380 km will help Gis? How do I have to start then?

You're already used to calculating percentages, you know, that fifteen percent, so I'm going to represent that it's 15/100, right, in a fraction that's 15 hundredths, so I'm going to calculate 15 hundredths of 380 Ok? So what is the strategy here? I take 380 and divide it by 100, so if I take 380 and I divide it by 100 by 100 parts, there are 100 groups here, it will be three, three times 100 of 300, 80 remains.

And then I transform it, so here I put a 0 then there will be eight, there will be a remainder of zero, doing the division completely so you can see what I realized, taking 380 and dividing it into 100 groups, which means that in each group of mine I will have 3. 8 km in each group, remember that I did that square hour here at home, my little group, I'm going to have 3. 8 km but how many groups do I have to take now I have to take 15 groups so I'm going to have to take 3.

8 and multiply it by 15, right or 15 times 3. 8 the order the order you take doesn't matter so I'm going to do 15 times 3. 8, 5 x 8= 40 goes 4, 8 x1= 8 with four are 12, then it will be 3 x 5= 15 goes 1 , 3 _ _ 0 is the same thing here as 57.

So it means that 15 hundredths or fifteen percent of 380 is equal to 57 as I'm talking about kilometers 57 Km. So it means that getting there by bike is going to take a while, right? I just have to walk 57 km a day a lot, right?

57 a day, right? But we ride a bike, I love riding a bike, OK? So this is one way, now I'm going to take advantage and talk about another way that you can also do the calculations with percentages, okay, because now you understand the concept here, right?

Why do I divide by 100 to form the groups and then I multiply it by how much I have here. You could have done it like this too guys, this calculation you would take the fifteen percent which represents 15 hundredths in the fraction of 380 then what would you do then you would multiply 15 by 380 so we would make 380 I will mark it as times because the word in mathematics symbolizes times, okay multiplication, multiply by 15 then here I will have 0, 8 x 5= 40, 5 x 3 are 15, 19 then put 0, 1 x 0= 0, 1 x 8= 8, 1 x 3= 3, and adding this from 17 gives 1, 3 4 5 to 5,700 so multiplying 15 by 380 gives 5,700 and then I take it and divide it by 100 which is the total here and 15 5,700 / 100 I can simplify 00 from here with 00 from here to make our calculation easier, it will stay the same 57. Look how quickly you want to do it here, people, but you must be saying Gis, why didn't you say this before, you could do it this way because I I wanted to explain to you the concept of division by 100, OK?

So now from now on you have the option you can choose to do it this way here first of dividing into 100 groups or you can do it straight away. You multiply and then divide by 100, okay? You choose the way you understand best, right people?

And then take the opportunity to subscribe to Gis's channel, you should leave your thumbs up for Gis too, which is very important to help Gis, right? And I'll see you in the next class, bye. .

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