I know that standard notation can be changed into scientific notation and vice versa while preserving the number of significant figures, like $100=1\times10^2$ which has one significant figure, or $100.=1.00\times10^2$ has three sig figs.
Now this one seems problematic: $1.0\times10^2$ has two sig figs. What is the standard notation of $1.0\times10^2$ with two sig figs?
Now this one seems problematic: $1.0\times10^2$ has two sig figs. What is the standard notation of $1.0\times10^2$ with two sig figs?
Yes, it is problematic. Significant figures are not actually used by practicing scientists. They are just a crutch for students to use while they are learning other more important things.
Professional scientists today will simply report the actual uncertainty of any measurement. So we would write something like “$100$ with a standard uncertainty of $3$” or “$100\pm 3$” or “$100(3)$”. All of these make the situation clear and unambiguous. It also allows much more precise statements of the uncertainty.
Whether you use standard, scientific, or engineering notation is not an issue.
