Gear microcontroller

dec = 0
function onTick()
    gear = input.getNumber(1)

end
function rd(num)
    if dec > 0 then
        local mult = 10^(dec or 0)
        return math.floor(num * mult + 0.5) / mult
    else
        return math.floor(num)
    end
end

function onDraw()
    screen.setColor(255,255,255)
    if gear == 0 then
        screen.drawTextBox(0,23,32,7,'n',0,0)
    elseif gear == -1 then
        screen.drawTextBox(0,23,32,7,'r',0,0)
    else
        screen.drawTextBox(0,23,32,7,rd(gear),0,0)
    end
end