When will i know when to add or when to subract

You will know when to add or subtract because of keywords and symbols.

Step-by-step explanation:

Most addition and subtraction problems have keywords that tell you what operation to use. For example, so keywords that tell you that you have to add are altogether, sum, together, and a few other words. Some examples of subtraction problems are less than, and a bunch of other words.

Hope This Helps :)

-6 is the correct option from the above given options