Explanation- Here’s an easier way to add negative numbers. Unlike adding positive numbers and positive numbers together and getting a larger positive number, do the opposite of what the symbol is telling you.
For example: -12 + 9 = -4
Instead of adding, I subtract 12 and 9 to get to 4 but the reasons the four is a negative is because any number from 0 to any higher value is always considered a negative.