Im not sure how your system is working but It should work like this

Input: 0.04

function round(num, numDecimalPlaces)
	local mult = 10^(numDecimalPlaces or 0)
	return math.floor(num * mult + 0.5) / mult
end


local input = yourvalue
local roundedvalue = round(input, 2) -- The function round returns your the Value (First Value is your number, second is how much Decimal places you want.
print(roundedvalue)