Opposite of Number

Today sixth graders are working with finding the opposite of a number.  Numbers that are opposites are the same distance from zero, but on different side of the number line.  For example, 4 and -4 are opposites because they are both 4 units from zero---positive four is the the right and negative four is to the left.  Another way to look at it is the opposite of -15 is 15.  

Check out this slide from learnzillion.com for more information.