uhhh, scale cannot be assigned to??????

uh, i made a healthbar script that changes size in comparison to the players health and on the last line above end it says scale cannot be assigned to;

local player = game.Players.LocalPlayer
local health = player.Health
local Denominator = 100

wait(1)
game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Health, false)

health.Changed:Connect(function()
	script.Parent.Frame.TextLabel.Text = health.Value .. " / " .. Denominator
	script.Parent.Frame.Size.X.Scale = health.Value / 100
end)