2 digits after the dot only or a good time counter

Hello,
I wrote a function and I want not any output with "12.123345342345234" I only need time left in Minutes or with only 12.12 (2 digits after the .)

Can someone help me how to do that?


function runsleep()

local randomTime = math.random(4*60, 20*60)

local randometimecount = 0

local a=5

toast("Schlafe für insgesamt: " .. randomTime/60 .. " Minuten")



    while randometimecount < randomTime do

        local leftime = randomTime/60-randometimecount/60

        toast("sleep time for " .. leftime .. "minutes" )

        randometimecount = randometimecount+a

        sleep(a)

    end

end