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    "# Lab 5\n",
    "\n",
    "How to verify if a number is a possible credit card number?\n",
    "In order to verify the check digit is correct, verify the following steps:\n",
    "\n",
    "* Supose the following number=\"5105105105105100\".\n",
    "* Convert the number into a list\n",
    "* Reverse the List\n",
    "* Starting from the left digit, double every second digit.\n",
    "* If double of a digit is more than 9, add the digits.\n",
    "* Sum all the numbers except the first one multiply by 9 and remove the unit\n",
    "\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "#Start by converting the number into a list\n",
    "number=\"5105105105105100\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "#convert a number into a list\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "#Convert stings into integers\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Starting from the left digit, double every second digit.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# If double of a digit is more then 9, add the digits.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Sum all the numbers except the first one\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# multiply by 9 and remove the unit\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "If the last number of variable numer is the same you reached, the check digit of the credit card is correct"
   ]
  }
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