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if I start counting where do I start usually I start from one so I start from one and then I go to two three four five when I keep doing this how far can I go I can keep going I can keep going forever so if I can keep doing this then what am I doing here I start from one and then I count forever if I do that then I get a family of numbers so I'm getting this big family here all the numbers that I will meet when I do this I'll first meet one then meet to then meet three I'll keep going then all these numbers that I meet belong to a family that I call natural numbers natural numbers so how do you meet all the members of this family called natural numbers you have to start from one and count forever start from one one and that's important here you're starting from one and then you're counting forever count forever now what if you say you know what I don't want to start from one but I'm gonna start from zero I'm gonna start from zero and then I'm gonna do the same thing that you did that is count one two three four forever so one two three four five keep going so this also keeps going and then how far do you go you go forever you will never reach a point where you say oh I can't count one more number at least I've reached my last number there is no last number so you'll keep going now if you do this what is the main difference or the only difference it's that you have included zero you've started from zero when you do that and you meet all these members of this family this family is called whole numbers whole numbers so if you have to meet all the members of this family then what must you do you have to start from zero start from zero and then do the same thing count forever count forever so you can notice that the difference between this family called natural numbers and this family called whole numbers is not very big the main difference or the only difference is that this family four whole numbers you start from zero confer ever four natural numbers you start from one and count forever another way to say the same thing is that natural numbers is that family of numbers that contains all the numbers from 1 and that keeps going forever and ever the family of whole numbers is all those numbers that are contained in natural numbers all the numbers are natural which is here plus an extra number one extra number you add to this family of natural numbers you get whole numbers and what is that number that's zero