How do I add numbers with scientific notation x10 with Negative power.

Question

Equation : 14.23 x 10^-19 + 8.1 x 10^-20 ?

How to solve and steps to solve.

Please help and organized.

Answer 1

Make both exponents the same.

14.23x10^-19 + 0.81x10^-19 = 15.04x10^-19 = 1.504x10^-18

And if you're interested in using significant figures, the answer would be 1.50x10^-18