How do i make i game currency but i dont get it on roblox wiki?

straight from the wiki:

game.Players.PlayerAdded:connect(function(player)
     local leaderstats = Instance.new("Model")
     leaderstats.Name = "leaderstats"
     leaderstats.Parent = player

     local money = Instance.new("IntValue") --We create a new IntValue
     money.Name = "Money" --this is the name you want the leader-stat to be when it shows up in-game.
     money.Value = 0 --this is the value of money the new player starts out with. To change this, you can add some more code (shown later)
     money.Parent = leaderstats -- Set the money object as a child of the leaderstats object.
 end)

This should make a leader board that can be used for currency then you just need to add or subtract numbers with whatever you want to do.