M.1.4.8

Apply and extend previous understandings of addition and subtraction to add and subtract rational numbers; represent addition and subtraction on a horizontal or vertical number line diagram. a. Describe situations in which opposite quantities combine to make 0. b. Understand p + q as the number located a distance | q | from p, in the positive or negative direction depending on whether q is positive                    or negative. Show that a number and its opposite have a sum of 0 (are additive inverses). Interpret sums of rational numbers by                                  describing real-world contexts. c. Understand subtraction of rational numbers as adding the additive inverse, p – q = p + – q ) . Show that the distance between two rational numbers on the number line is the absolute value of their difference, and apply this principle in real-world contexts. Apply properties of operations as strategies to add and subtract rational numbers.