This was taught in Elementary school and sixth grade. Number line will looks something like: -5 -4 -3 -2 -1 0 1 2 3 4 5 and so on in both directions, does that help? if not.... How you tell is because one side (the left) is negative numbers and the other side (the right) is positive, and if ur numbers are the same such as positive/negative then which ever one is closer to the 0 (with the negative side) and with the positive side which one is farthest away from the 0.. hope it helped, please excuse the improperness my fingers are killing me..