{
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Numbers and Integer Math\n",
        "\n",
        "Watch the full [C# 101 video](https://www.youtube.com/watch?v=jEE0pWTq54U&list=PLdo4fOcmZ0oVxKLQCHpiUWun7vlJJvUiN&index=5) for this module."
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "## Integer Math\n",
        "\n",
        "You have a few `integers` defined below. An `integer` is a positive or negative whole number.\n",
        "> Before you run the code, what should c be?"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "## Addition"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "dotnet_interactive": {
          "language": "csharp"
        }
      },
      "outputs": [
        {
          "name": "stdout",
          "output_type": "stream",
          "text": [
            "24\r\n"
          ]
        }
      ],
      "source": [
        "int a = 18;\n",
        "int b = 6;\n",
        "int c = a + b;\n",
        "Console.WriteLine(c);"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "## Subtraction"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "dotnet_interactive": {
          "language": "csharp"
        }
      },
      "outputs": [
        {
          "name": "stdout",
          "output_type": "stream",
          "text": [
            "12\r\n"
          ]
        }
      ],
      "source": [
        "int c = a - b;\n",
        "Console.WriteLine(c);"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "## Multiplication"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "dotnet_interactive": {
          "language": "csharp"
        }
      },
      "outputs": [
        {
          "name": "stdout",
          "output_type": "stream",
          "text": [
            "108\r\n"
          ]
        }
      ],
      "source": [
        "int c = a * b;\n",
        "Console.WriteLine(c);"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "## Division"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "dotnet_interactive": {
          "language": "csharp"
        }
      },
      "outputs": [
        {
          "name": "stdout",
          "output_type": "stream",
          "text": [
            "3\r\n"
          ]
        }
      ],
      "source": [
        "int c = a / b;\n",
        "Console.WriteLine(c);"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Order of operations\n",
        "\n",
        "C# follows the order of operation when it comes to math. That is, it does multiplication and division first, then addition and subtraction.\n",
        "> What would the math be if C# didn't follow the order of operation, and instead just did math left to right?"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "dotnet_interactive": {
          "language": "csharp"
        }
      },
      "outputs": [
        {
          "name": "stdout",
          "output_type": "stream",
          "text": [
            "13\r\n"
          ]
        }
      ],
      "source": [
        "int a = 5;\n",
        "int b = 4;\n",
        "int c = 2;\n",
        "int d = a + b * c;\n",
        "Console.WriteLine(d);"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "## Using parenthesis\n",
        "\n",
        "You can also force different orders by putting parentheses around whatever you want done first\n",
        "> Try it out"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "dotnet_interactive": {
          "language": "csharp"
        }
      },
      "outputs": [
        {
          "name": "stdout",
          "output_type": "stream",
          "text": [
            "18\r\n"
          ]
        }
      ],
      "source": [
        "int d = (a + b) * c;\n",
        "Console.WriteLine(d);"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "You can make math as long and complicated as you want.\n",
        "> Can you make this line even more complicated?"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "dotnet_interactive": {
          "language": "csharp"
        }
      },
      "outputs": [
        {
          "name": "stdout",
          "output_type": "stream",
          "text": [
            "25\r\n"
          ]
        }
      ],
      "source": [
        "int d = (a + b) - 6 * c + (12 * 4) / 3 + 12;\n",
        "Console.WriteLine(d);"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "## Integers: Whole numbers no matter what\n",
        "\n",
        "Integer math will always produce integers. What that means is that even when math should result in a decimal or fraction, the answer will be truncated to a whole number.\n",
        "> Check it out. WHat should the answer truly be?"
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "dotnet_interactive": {
          "language": "csharp"
        }
      },
      "outputs": [
        {
          "name": "stdout",
          "output_type": "stream",
          "text": [
            "3\r\n"
          ]
        }
      ],
      "source": [
        "int a = 7;\n",
        "int b = 4;\n",
        "int c = 3;\n",
        "int d = (a + b) / c;\n",
        "Console.WriteLine(d);"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Playground\n",
        "\n",
        "Play around with what you've learned! Here's some starting ideas:\n",
        "> Do you have any homework or projects that need math? Try using code in place of a calculator!\n",
        ">\n",
        "> How do integers round? Do they always round up? down? to the nearest integer?\n",
        ">\n",
        "> How do the Order of Operations work? Play around with parentheses."
      ]
    },
    {
      "cell_type": "code",
      "execution_count": null,
      "metadata": {
        "dotnet_interactive": {
          "language": "csharp"
        }
      },
      "outputs": [
        {
          "name": "stdout",
          "output_type": "stream",
          "text": [
            "Playground\r\n"
          ]
        }
      ],
      "source": [
        "Console.WriteLine(\"Playground\");"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Continue learning\n",
        "\n",
        "There are plenty more resources out there to learn!\n",
        "> [⏩ Next Module - Numbers and Integer Precision](https://raw.githubusercontent.com/dotnet/csharp-notebooks/main/csharp-101/05-Numbers%20and%20Integer%20Precision.ipynb)\n",
        ">\n",
        "> [⏪ Last Module - Searching Strings](https://raw.githubusercontent.com/dotnet/csharp-notebooks/main/csharp-101/03-Searching%20Strings.ipynb)\n",
        ">\n",
        "> [Watch the video](https://www.youtube.com/watch?v=jEE0pWTq54U&list=PLdo4fOcmZ0oVxKLQCHpiUWun7vlJJvUiN&index=5)\n",
        ">\n",
        "> [Documentation: Numbers in C#](https://docs.microsoft.com/dotnet/csharp/tour-of-csharp/tutorials/numbers-in-csharp?WT.mc_id=Educationalcsharp-c9-scottha)\n",
        ">\n",
        "> [Start at the beginning: What is C#?](https://www.youtube.com/watch?v=BM4CHBmAPh4&list=PLdo4fOcmZ0oVxKLQCHpiUWun7vlJJvUiN&index=1)"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {},
      "source": [
        "# Other resources\n",
        "\n",
        "Here's some more places to explore:\n",
        "> [Other 101 Videos](https://dotnet.microsoft.com/learn/videos?WT.mc_id=csharpnotebook-35129-website)\n",
        ">\n",
        "> [Microsoft Learn](https://docs.microsoft.com/learn/dotnet/?WT.mc_id=csharpnotebook-35129-website)\n",
        ">\n",
        "> [C# Documentation](https://docs.microsoft.com/dotnet/csharp/?WT.mc_id=csharpnotebook-35129-website)"
      ]
    }
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