How do I do arithmetic with attribute?

SecTime = game.workspace:GetAttribute("Second")
while true do
	wait(1)
	SecTime = SecTime + 1
	game.Workspace:SetAttribute("Second", SecTime)
end

It gives me a error, attempting to do arithmetic at line 4. How do i fix it

Hello!

You see, strings can not be added, subtracted, multiplied, whatever, with a number. What you can do, is to first convert the string to a number, and then convert it back to a string.

local string = "200"

local finalnumber = tonumber(string) + 300

local finalstring = tostring(finalnumber)

If you're confused, you can go here for an article about strings and their behavior.

I hope this helps!

your code was much deprecation

local start = os.time()

while true do
	local now = os.time()
	workspace:SetAttribute("Second", math.floor(now - start))
	wait(0.5)
end