Quickchange - The game

local currency = "%s USD"
local coins = {2,1,0.5,0.2,0.1,0.05,0.02,0.01}

math.randomseed(os.time())

local total = math.random(1,10) + math.random(0,99)/100
local given = total + math.random(1,5) + math.random(0,99)/100
print("Total price: "..currency:format(total))
print("Money given by the customer: "..currency:format(given))

local solution,try = {},{}
for k,v in pairs(coins) do
    local am = math.floor(given/v)
    solution[v] = am
    given = given - am*v
    given = math.floor(given*100+0.5)/100
    io.write("How much will you give of "..currency:format(v).."? ")
    try[v] = tonumber(io.read()) or error("tonumber: sigh",0)
end

print(" Currency | Solution | Entered | Result")
local padding = "%9s | %8s | %-7s | "
for k,v in pairs(coins) do
    local yeuy = solution[v]==try[v] and "GOOD" or "YOU GOT AN ERROR HERE"
    print(padding:format(currency:format(v),solution[v],currency:format(try[v]))..yeuy)
end