why does it not change the text when the value is changed?

local leaderstats = game.Players.LocalPlayer.leaderstats
local level = leaderstats.Level
local exp = level:WaitForChild("EXP") 
local levelDisplay = script.Parent.Level
local expDisplay = script.Parent.Exp

exp.Changed:Connect(function()
expDisplay.Text = "Exp: "..exp.Value "/1000"	
end)
level.Changed:Connect(function()
	levelDisplay.Text = "level: "..level.Value	
end)

changing the level works but not the exp i get an error Error attempt to call field 'Value' (a number value)

local script in a screenGUI

Try this:

local Player = game.Players.LocalPlayer
repeat wait() until Player.leaderstats
local leaderstats = Player.leaderstats