How to use math.random?

I'm having a bit of trouble with this. It says I can't use math.random, but I'm not sure what else to use. 'Up' is a member of the Player (There's a script for it). Could someone help me out?

s = game.Workspace:GetChildren()

function Down()
    for i,v in pairs(game.Workspace:GetChildren()) do
            if v.Name == "SpawnLocation" then
                plr.Character:MoveTo(math.random(1,v.Position))
                a = false
            end
    end
end

function Up()
    for i,v in pairs(game.Workspace.Lobby:GetChildren()) do
        if v.Name == "SpawnLocationU" then
            plr.Character:MoveTo(math.random(2,v.Position))
        end
    end
end

game.Players.PlayerAdded:connect(function(p)
    game.Workspace.CharacterAdded:connect(function(char)
        if p.Up.Value == false then
            Down()
        elseif p.Up.Value == true then
            Up()
        end
    end)
end)