+4 Hello,
I was a math teacher. My first priority was always to teach students tricks about math.
Yes, some online calculators are reliable like sig fig calculator on calculators.tech. Actually, the reason I like this calculator also describes which rules are applied to calculate significant figures of your entered number.
+4 I suggest you try this calculator: https://www.calculators.tech/standard-form-calculator because most of the time I used this and it always gives me the right answer.
As per the 1st answer, these numbers are already in standard form there is no need to convert them.
if you want to write them in scientific notation use above calculator. answers will be following.
0.0073256 =\( 7.3256 \times10^{- 3}\)
0.05 = \(5.0 \times 10^{-2}\)
0.5 = \(5 \times 10^{-1}\)
1200256500 = \(1.2002565 \times 10^9\)
.