Class 6-10 - Playing with Numbers

In this session, I'll discuss more about numbers. starting with numbers in general form. To understand this, let's take a number 52. if I break it down, now what is the meaning of breaking it down? I can write 52 as 50 + 2 This is a two digit number. 2 is actually at units place. 5 is at tens place. I am sure all of you know this. So, I can write the... ... the same 52 as 5 into 10... ... because 5 is at tens place. Plus... ...2 into 1 because 2 is at ones place. So, I can represent 52 as (5 x10)... ... + (2 x 1). Let's take one more number. Let's take 37. So how do I write in this format? 37 can be written as... ...since 3 is at tens place or the place... ... value is 10, we'll write (3 x 10)... ... + (7 x 1) . So 37 is (3x10) ... ...+ (7x 1). Why 7 x 1? Because 7 is at ones place. All of you know writing numbers this way. Now, instead of numbers, if I want to generalize and take... ...any 2 digit number. I'll, instead of using any two... ...digits, I'll use any two digits. What is the meaning of any two digits? It's AB. So, if I take a 2 digit number... AB, I can write it as, A is at tens place,... ... B is at ones space. I can write this as (10 x A)... ...+ (b x 1). Instead of AB,... if it is lets say BA, then it will become (10 x b)... ...+ (a x 1). This is how we represent... ...any 2-digit number, right? By using variables, right. Meaning.... ...of any is nothing but in maths we can use variables over there. So, this A is a single digit. B is also a single digit, when I represent AB as a 2-digit number. A and B can represent digits from 0 to 9. Now, let's take a 3-digit number. Let's take 356. How do I write 356. I can break it down as 300... ... +50 + 6. Now, 3 is at hundreds place, so I can write (100 x 3)... ... + 5 is at tens place, so that's (10 x 5)... ...+ 6 is at ones place, so that (1 x 6). in a similar fashion... ... we can write 427 as (100 x 4) ... ... + (2 x 10) or (10 x 2)... ... to follow the same order. (100 x 4) + (10 x 2)... ... + (1 x 7). That's how we can... ... breakdown 427. In general,... ... a 3-digit number ABC can be, ABC which is made up of digits A, B and C,... ... can be written as ABC = 100A... ...+10B + 1C because A is at hundreds place... ...B is at tens place and C is at ones place. Same way, suppose of it is CAB, how will I write? 100C + .... ...10A + 1B. Or CBA can be written... Hyundai E&C less NB less one 80