Table of values returning nil?

After some testing I realized roblox sometimes has this weird problem where lets say you do 2+2 and your answer will be 4, but in the computer it's actually something like 4.00000000000001. I'm not sure why it does this, but that's the issue here. When I did

while percentage < 1 do
	print(percentage)
	print(percentage * 10)
	local product = percentage * 10
	print(list[percentage * 10])
	numFloor = math.floor(product)
	print(list[numFloor ])
	print(numFloor)
	    percentage = percentage + 0.1
	    wait()
end

print(list[numFloor ]) never resulted in a nil number. The only problem is lets say .3x10=3.000000001 mathfloor would change it to 3, but sometimes .7x10 = 6.99999999998 or something like that, so then the number will become 6.

To combat this you can use this

local function round(n)
	return math.floor(n + 0.5)
end

Final working script:

local percentage = 0.1
 
local list = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

local function round(n)
	return math.floor(n + 0.5)
end

while percentage < 1 do
	local product = round(percentage * 10)
	print(list[product])
	    percentage = percentage + 0.1
	    wait()
end
	--for index 3, 8, and 10, the table outputs nil.(list[percentage * 10]) = nil)
	print("----------------------------------")
	 
	local num = 1
	 
	print(list[0.1 * 10])
	print(list[0.2 * 10])
	print(list[0.3 * 10])
	print(list[0.4 * 10])
	print(list[0.5 * 10])
	print(list[0.6 * 10])
	print(list[0.7 * 10])
	print(list[0.8 * 10])
	print(list[0.9 * 10])
	print(list[1 * 10])