Floating-point numbers in modern computers are almost exclusively one of a few types of IEEE-defined floating-point types that differ only in how many bits are used for each number.
But the concept of a floating-point representation is not limited to what the vast majority of actual applications are using. You're being asked a theoretical question about another kind of floating-point representation that could be used.
The "leading digit is always $1$" trick only works in binary, and therefore you cannot use it in base ten. There is a bit of ambiguity in the question regarding whether "two digits in the fraction" means they want numbers like
$2.34 \times 10^1$ or like $0.34 \times 10^1.$
In the absence of any other indication, if I had to guess,
I would guess they mean $0.34 \times 10^1$ just because the other way is ten times as many numbers to write.
But if you can ask the person who assigned this question, I would recommend you do.
Even if we only use two fractional digits (like $0.34 \times 10^1$),
there are still a few hundred possible numbers.
If you really literally must list them all, perhaps you can get them printed out by computer. A simple spreadsheet can do the job.
But I suspect that only only need to list enough of them in a pattern so that it is clear how you would fill in the missing numbers (and how many there would be),
much the way that if I write $1,2,3,4,\ldots,59,60$ you can see I have in mind the first sixty positive integers.
Again, that is something to ask the person who assigned this if you can.
