How do I round to the nearest hundred?

I have this code:

Code:someFunction() {
if (someVar > 2000) {return 2;}
if (someVar > 1900) {return 1.9;}
if (someVar > 1800) {return 1.8;}
if (someVar > 1700) {return 1.7;}
if (someVar > 1600) {return 1.6;}
if (someVar > 1500) {return 1.5;}
if (someVar > 1400) {return 1.4;}
if (someVar > 1300) {return 1.3;}
if (someVar > 1200) {return 1.2;}
if (someVar > 1100) {return 1.1;}
if (someVar > 1000) {return 1;}
if (someVar > 900) {return 0.9;}
if (someVar > 800) {return 0.8;}
if (someVar > 700) {return 0.7;}
if (someVar > 600) {return 0.6;}
if (someVar > 500) {return 0.5;}
if (someVar > 400) {return 0.4;}
if (someVar > 300) {return 0.3;}
if (someVar > 200) {return 0.2;}
if (someVar > 100) {return 0.1;}
}Of course it's dumb.

It goes up to 2,000 but "someVar" could be a lot larger than that, maybe millions or billions. What is the smart way to achieve what I want?

Please assume some kind of shell scripting or pseudo code.

TIA