is there a way for a variable to be shared between scripts , not functions ?

example variable's value is "0" , localscript from startergui updates varibale to "1" and script from workspace.part takes the variable's value for something It looks like something like this:

Local variable = "0" --I don't know where to put this

for script 1 ; Script location : game.StarterGui ~~ Script Type : Local script

variable = "1"

for script 2 ; Script Location : game.Workspace.Part

game.Workspace.Part.ClickDetector.MouseClick:Connect(function(Player)
Local Answer = variable + "1"
print(variable.."+ 1 = " .. Answer)
end)

the print should be "1 + 1 = 2

Lua is case sensitive, the datatype local must be defined with a lowercase L. You can also use the global array _G to store universal variables.

Lua will also perform the numerical operation with the two String expressions seen at line 2 of your second Script. This will result in a float 2.0 which will be concatenated into a result that looks like so: 2.0 + 1 = 2.0.

I also highly suggest you leave numerical operations to numerical datatypes.

_G.Variable = 1

workspace.Part.ClickDetector.MouseClick:Connect(function()
    local Number = _G.Variable
    print(Number.." + "..Number.." = "..(Number + Number)
end)