TenMarks teaches you how to represent and compare integers.
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Learn about Integers on a Number Line In this video we will learn how to map integers on a number line and use it to compare integers as well. So there are three questions in this video the first one asks us to graph the value -3 on the number line and the second question and third question will come back to it and the second question and the third question will come back in. So let’s actually scroll down, I’ve actually already drawn a number line okay? So the first question that we’re solving has to do with we need to graph -3 on a number line, that’s the question. That’s what we need to do, so let’s understand what a number line is first. The way you draw number line is we see a straight line and it always start at the center being 0 and then to the right of 0 we make markers which are in into positive integers. So you go +1, +2 and so on and this can go on forever and similarly on the left side of 0 you got the negative integers which are -1, -2, and so on okay? So in order for us to map number 3 on this line what we need to do is look at where number 3 exist which is right here right? So for us to map it all I need to do is put a circle or a dot right above this number 3 marker, that is the answer, so that’s how you do it, so this has been graphed or mapped okay? Now let’s look at the second question which I’ll scroll up and see what they’re asking us for. The second question says that there is a statement which is -6 and -4 and what we have to do is figure out how do I replace this particular symbol with either a < or a > or an = sign, so in a nut in a nutshell what we need to do is determine if -6 is less than -4 or equal to -4 and it's asking us to use the number line to compare, so lets go to the space where we have a little bit of extra space okay? So we’ll start from here and let me draw the number line again, so what do we have to do, we need to do is figure out is—lets use this space -6 right and -4 I have to put a symbol in here is the symbol > or < or =? So the first thing we’re going to do right is I am going to graph both -6 and -4 on the line okay? So here’s the number line again, the same one we used, so -6 is right above here right? So that’s one marker and -4 is right here, so this is -4, this is -6, the rule of thumb you need to remember is that the number to the right is always greater, so what does that mean? That means that -4 is greater because it is to the right of -6, so this is greater -6 is less than -4, so the answer here is actually the lesser sign because -6 is actually less than -4. Now lets look at the third question, third questions says estimate the values for points A through G and order from least to the greatest. So we are given all these prints, so let’s actually write this down right, I’m going to write down A B C D E F G and let’s write down the values, what’s the value of A? Its right in line above the marker for -8, B is +8, similarly you can see C is 0, D is -2 you see what I’m doing right? E is between -6 and -8 exactly halfway between 6 and 8 on the negative scale so it has to be -7 right? It's not clearly marked but I can see that visually, F is right here between -4 and -5 so it's negative and then G is +3 because it's between +2 and +4 so this must be +3, exactly halfway between them, so this is +3 right? So if I raise them in order, well the least we have to mark them from least to the greatest right, so what is the lowest number which is to the left right? We know that the sequence says the number to the left is always the lowest, so this should be their lowest greatest order anyway. So I can simply copy it by saying A, E, F, D, C and then G and then B because I’m simply moving from left to right. So if I can just test it A is -8, D is -2 that is the answer to question three. So lets quickly recap what we’ve learned, what we’ve learned is the following that first a number line can easily be drawn by drawing a flat line and then putting markers on it, the marker for 0 is in th