Hi. I keep getting the error " attempt to call upvalue 'raritys' (a table value)"?

If anyone can help i'd be very grateful. :)

local raritys = {
    Common = 5,
    Uncommon = 3,
    Rare = 1,
    Legendary = 0.2
}
local crateInUse = true

local function openCrate(chance)
    if crateInUse == true then
     local items = {}
     local result 
     local frametimes = math.random(20,30)
     for _,Item in pairs(game.ReplicatedStorage.Items:GetChildren()) do
        local rarNumber = raritys(Item.Rarity.Value)
        local times = math.max(rarNumber/chance)
        end
    math.randomseed(tick())

    for num = 1,frametimes+5 do
        local item = items[math.random(#items)]
        local newicon = script.Parent.Unboxing.Inner.Icon:Clone()
        newicon.Visible = true
        newicon.Parent = script.Parent.Unboxing.Inner
        newicon.Image = item.ImageID.Value
        newicon.Position = UDim2.new(0,100*(num-1),0,0)
        if num == frametimes then
            result = item
            crateInUse = false
        end

    end
    end
end


script.Parent.TextButton.MouseButton1Click:Connect(openCrate(2))