How do I print/round a number to a given number of decimal places? is the question you were looking for. Check out sprintf for the juicy details :)

print sprintf("%.1f", 490.408163265306), "\n"; # 1 decimals
print sprintf("%.2f", 490.408163265306), "\n"; # 2 decimals
print sprintf("%.3f", 490.408163265306), "\n"; # 3 decimals
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Update: Aw, got beat like usual.

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