Question

check my answer pls

http://prnt.sc/clntrm

Answer 1

Which mathematical operation is called for here?

Answer 2

scientific notation....a few different ones

Answer 3

That's a convention, not a math operation.
I've checked your answer mainly for format, and notice you're repeatedly including the "=" symbol on the same line of type.

Each time you write an equation, involving "=," please begin a new line for the next equation.

Take a hard look at y our answer. Does it make sense, in terms of the magnitudes involved?