diff --git a/01_grundlagen/unterricht/tag08/06_guard-function-volume-tube.html b/01_grundlagen/unterricht/tag08/06_guard-function-volume-tube.html
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+<!doctype html>
+<html lang="de">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Zylindervolumen berechnen (tube) mit Guard</title>
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.8/dist/css/bootstrap.min.css" rel="stylesheet" />
+  </head>
+  <body>
+    <main>
+      <div class="container py-5">
+        <h1>Zylindervolumen berechnen (tube) mit Guard</h1>
+      </div>
+    </main>
+    <script>
+      'use strict';
+
+      const BASE_COST_PER_UNIT = 0.7;
+      const COST_PER_CC = 0.001;
+
+      const height = 80;
+      const diameter = 10;
+
+      /**
+       * Funktion zum Berechnen vom Zylindervolumen
+       */
+      const calcTubeVolume = (diameter = 10, height = 80) => {
+        // Guard
+        if (isNaN(diameter) || isNaN(height) || diameter < 0 || height < 0) return NaN;
+
+        const radius = diameter / 2;
+        // cylindricalVolume = π × radius² × height
+        const volume = Math.PI * Math.pow(radius, 2) * height;
+        return volume;
+      };
+
+      /**
+       * Funktion zum Berechnen vom Zylindervolumen (Kurzschreibweise)
+       */
+      const calcTubeVolumeShort = (diameter, height) =>
+        isNaN(diameter) || isNaN(height) || diameter < 0 || height < 0
+          ? NaN
+          : Math.PI * Math.pow(diameter / 2, 2) * height;
+
+      /**
+       * Funktion zum Berechnen der Versandkosten
+       */
+      const calcShippingCost = (volume) => {
+        // Guard
+        if (isNaN(volume)) {
+          console.warn('wrong volume data type');
+          return NaN;
+        }
+
+        // shippingCost = volume × costPerCC + costPerUnit
+        const cost = volume * COST_PER_CC + BASE_COST_PER_UNIT;
+        return cost;
+      };
+
+      /**
+       * Funktion zum Berechnen der Versandkosten (Kurzschreibweise)
+       */
+      const calcShippingCostShort = (volume) => (isNaN(volume) ? NaN : volume * COST_PER_CC + BASE_COST_PER_UNIT);
+
+      const tubeVolume = calcTubeVolume(); // calcTubeVolume(diameter, height);
+      const shippingCost = calcShippingCost(tubeVolume);
+
+      console.log(shippingCost); // => 6.983185307179587
+      console.log(calcShippingCostShort(calcTubeVolumeShort(10, 80))); // => 6.983185307179587
+    </script>
+  </body>
+</html>
diff --git a/01_grundlagen/unterricht/tag08/07_rest-default-parameter.html b/01_grundlagen/unterricht/tag08/07_rest-default-parameter.html
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+<!doctype html>
+<html lang="de">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Rest- und Defaultparameter</title>
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.8/dist/css/bootstrap.min.css" rel="stylesheet" />
+  </head>
+  <body>
+    <main>
+      <div class="container py-5">
+        <h1>Rest- und Defaultparameter</h1>
+      </div>
+    </main>
+    <script>
+      'use strict';
+
+      // Defaultparameter
+      const add = (n1 = 0, n2 = 0) => {
+        return Number(n1) + Number(n2);
+      };
+
+      console.log(add(1, 2)); // => 3
+      console.log(add(5, '12')); // => 17
+      console.log(add(1)); // => 1
+      console.log(add()); // => 0
+
+      // Restparameter (...)
+      const sum = (...numbers) => {
+        return numbers.reduce((a, b) => Number(a) + Number(b), 0);
+      };
+
+      console.log(sum(1, 2)); // => 3
+      console.log(sum(1, 2, 3, 4, 5)); // => 15
+      console.log(sum(10, 20, 30)); // => 60
+
+      // Restparameter (...names)
+      const greetWith = (greeting, ...names) => {
+        names.forEach((name) => {
+          console.log(`${greeting}, ${name}!`);
+        });
+
+        // return `${greeting}, ${names}!`;
+      };
+
+      greetWith('Hey', 'Goldy');
+      greetWith('Hi', 'Stefan', 'Florian', 'Benjamin', 'Chrsitian', 'Philippe');
+    </script>
+  </body>
+</html>