In this standard we will learn about how to add and subtract rational numbers.No.1, What are rational numbers: a rational number is a type of real number, which is in the form of p/q where q is not equal to zero.No.2, how to add rational numbers: Step 1: Convert the rational numbers to be added into rational numbers with positive denominators. Step 2: Find the LCM of the denominators and express each rational number with this LCM as the denominator. Step 3: Add the new numerators and write them as the sum.No.3, How to subtract rational numbers: Subtracting rational numbers uses the same steps as adding. The only thing different is you subtract