Okay, so welcome to the course. So let us now use for loop to do some basic mathematics. The reason why I'm doing this basic math with for loop is to teach you how to use for loop. So let me ask you this question, what is one plus two, of course it is three. So what is one plus two plus three is six. So now if I want to do it in Python, I have to write, print.

One plus two, c plus c six, three, then print. One plus two plus three, it will print six. So now if I want to print four stand number, so one plus two plus three plus four, plus five plus six plus seven plus eight plus nine plus 10. So what will be the result? It is 55. So now, if I do it, try to do it in a for loop.

So what can be done? So people often ask why you do make us do all these things, we have a calculator, we can add many numbers we want, right. So, basically the point of doing this is, is to show you or to make you understand how Python like programming language can be used to add search numbers up to whatever level so here we are just adding 10 numbers. But if you want to add hundred numbers thousand numbers, Python can do it easily with a for loop. Now, here I'll be using a for loop to add up a range of numbers so for i in range. So first, let us do it with a small range.

I'll do it with three, give a colon and Answer is equal to answer. Class I know before this for loop, I have to give assign a value to this answer. So first I have to assign answer to zero. Then I'm starting the for loop, for our in range three, answer is equal to answer plus one now what is happening here whenever this I will get incremented answer will also get incremented when i is equal to zero answer will be zero plus zero is zero. So when I is equal to one answer will be zero plus i that is 120 plus one is equal to one, so an answer will be two then I will be two then answer will be one plus two, that is three. So in this way, every time answer will be incremented by one now print answer let me just indent it works Yeah.

So just run it. See what you got 01213 so how you got it? So first I have assigned answer to zero okay, so answer is equal to zero then I've written for i in range three answer is equal to answer plus i. So first initially answer is zero, then zero plus zero when i is equal to zero, so this one will also be zero plus zero equal to zero, so when i equal to one, then answer is zero. So zero plus one is equal to one, so you got one second 10. When answer is equal to two, then one plus two is equal to three, see what three here so in this way, the for loop is running.

Now if you change The range you change it to 10 and just run it see what this now the first 10 numbers some is 55 the sum of first and number 75 but here we got 45 because it's starting from zero I starting from zero, so, just increase it to 11 and you will get the first sum of 10 numbers Okay, this now, let me show you something I hope you understand this concept of for loop how this answer is getting incremented every time now here I'll show you something more. So answer is equal to zero then for i in range suppose 10 answer is equal to answer class. I Then, here I write, print, look at carefully what I'm writing first give a comma i give a comma and after that right number when added GIS answer. So now, when I print this on when I execute this program, it will do work.

In the place of AI, the value will be changed in the place of answer the value will be changed and the rest of the code that we've written within quotes will be printed as it is. So forced when is equal to zero. What will be my answer first zero number when added gives zero first one number when added gives one first two numbers when added gives three. So, in this way it will run. So, just run it I got a syntax error and what is a syntax error Can anyone tell me see here it is showing I haven't provided a comma over here. So now I have provided the comma.

Now run. See you got the result. So for zero numbers when added gives zero, first one number when added gives one first two number when added gives three. In this way you got first nine numbers up to so suppose if you want to increase up to 10, so increase the range and you got forced in numbers when added gives 55 So, in this way we can get we can generate any sum of numbers. Now, suppose I will show you this answer equal to zero for i in range five on sorry call to answer plus i. So print answer now what I will do is here I will just remove the indent and see what will happen.

See what you got? You got 10 So, first five number when added you get 10 okay because Now, what I did is I removed this print statement from the for loop and took it out from the for loop and print it separately. So, whenever this print statement is is indented that means, it is within the for loop, but now I removed the indentation and now it is out of the for loop. So, whenever it is out of the for loop, it will just print you the final result not every time the loop is executing, it will print. So, whenever you remove the indentation and if you if you bring out the print statement out of the for loop, it will give you the final result but whenever you will use this print statement within the for loop it will execute and print each of the iteration whenever the up to which the for loop is running.

So, see you got this whenever you print the print statement within the follow and now just copy it and paste it over here and remove the indentation Run it. See you got the final reason, the last reason so this is the importance of indentation and this is how we can use a for loop. So see you the next video till then keep practicing. Thank you