Answer:
multiple and divide are depending on the powers ( sometimes the numbers before the scientific n.)
If the power neg- , it's going down
like this 10^-5 = 1/10^5
If the power pos+ , it's the same idea but different in signs .
Adding and subtracting are depending on numbers ( If the scientific n. is the same number) .
for example:
3x10^5 + 4x10^5 = (3+4)x10^5 = 7x10^5