you have to multiply the two standard forms together
(8 x 10^-7) x (5.45 x 10^9)
to multiply multiply the two numbers together then the 10 powers, and when multiplying powers you simply add the two powers together.
43.6 x 10^(-7 + 9)
43.6 x 10^2
then put this into standard form
4.36 x 10^3 (as standard form allows for only 1 number infront of the decimal place) and to get back to 43.6 x 10^2 you have to multiply by 10 so this = 4.36 x 10 x 10 x 10 =4.36 x 10^3
