I got this error: attempt to perform arithmetic on upvalue 'RarityItems'(a table value) help?

local Raritytimes = {
    ["Common"] = 80,
    ["Uncommon"] = 15,
    ["Rare"] = 5,
}

local CrateInude = false

local function opencrate(Chance)
    if CrateInude == false then
        CrateInude = true
        local items = {}
        local frametimes = math.random(30,32)
        local rewardbutton
        for i,v in pairs(game.ReplicatedStorage.Items:GetChildren()) do
            local rarnumber = Raritytimes[v.Rarity.Value] or 1
            local mathmatical = math.max(Raritytimes+Chance)
            for i = 1,mathmatical do
                table.insert(items,v)
            end
        end

        math.randomseed(tick())     

        for i = 1,frametimes+5 do
            local item = items[math.random(#items)]
            local newsapme = script.Parent.Unboxing.SampleItem:Clone()
            newsapme.Visible =true
            newsapme.Parent = script.Parent.Unboxing.inner
            newsapme.Icon.Image = item.Image.Value
            newsapme.ItemName.Text = item.Name
            newsapme.Position = UDim2.new(0,100*(i-1),0,0)
            if i == frametimes then
                rewardbutton = newsapme
            end
        end
        for num = 1,(rewardbutton.Position.X.Offset - (255+math.random(-40,40)))/15 do
            for i,v in pairs(script.Parent.Unboxing.inner:GetChildren()) do
                v.Position = UDim2.new(0,v.Position.Offset-15,0,0)
                if v.Position.X.Offset <= -150 then
                    v:Destroy()
                end
            end
            wait(0.01 * 1.05 ^ (num-105)/2)
            script.Tick:Play()
        end
    end
end

opencrate(0)

The error is: 12:05:27.690 - Players.shootthegame.PlayerGui.BasicCrate.LocalScript:17: attempt to perform arithmetic on upvalue 'Raritytimes' (a table value)

(the error is in line line 17)

Can anyone help me fix the problem?