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.
7.NS.1.d
Apply properties of operations as strategies to add and subtract rational numbers.
7.NS.2
Apply and extend previous understandings of multiplication and division and of fractions to multiply and divide rational numbers.
7.NS.2.c
Apply properties of operations as strategies to multiply and divide rational numbers.