Why is my script not working?

This is sort of like an admin command but it isnt admin, it is a calculator type thing.

Script Below

game.Players.PlayerAdded:connect(function()
    for i,v in pairs(game.Players:GetChildren()) do
        v.Chatted:connect(function(msg)
        if msg:lower():sub(1,5) == "math " then
            m = Instance.new("Message")
        elseif v.Chatted == "math 0 + 1 = "
            then m.Parent = game.Workspace
            m.Text = ("1")

end
end)
end
end)