200
800
I think your question is asking how you would round 17.521 to the nearest number with 1 significant figure...if that's the case, it would round to 10.
700 or 650.8
2000
Well, darling, if you want to round 38562.7 to 1 significant figure, you'd end up with 40000. Yes, you heard me right, 40,000. That's just the way the cookie crumbles when it comes to significant figures.
200
It's already there.
7000
0.1
2,000,000
10000000
9000
It is 0.01
0.9
12
800
100