diff --git a/.github/workflows/check_lesson_06_pr.yaml b/.github/workflows/check_lesson_06_pr.yaml
new file mode 100644
index 000000000..8c667d78e
--- /dev/null
+++ b/.github/workflows/check_lesson_06_pr.yaml
@@ -0,0 +1,32 @@
+name: Check Lesson 06 Pull Request
+
+on:
+  pull_request:
+    branches: [ "main" ]
+    paths:
+      - "lesson_06/expression/**"
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Use Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: '20.x'
+
+    - name: Build Shared Lib with Node.js
+      working-directory: ./lib/javascript/codedifferently-instructional
+      run: npm ci
+
+    - name: Build Lesson 06 with Node.js
+      working-directory: ./lesson_06/expression
+      run: |
+        npm ci
+        npm run check
\ No newline at end of file
diff --git a/.github/workflows/check_lesson_06_quiz.yaml b/.github/workflows/check_lesson_06_quiz.yaml
new file mode 100644
index 000000000..deaea1baa
--- /dev/null
+++ b/.github/workflows/check_lesson_06_quiz.yaml
@@ -0,0 +1,32 @@
+name: Check Lesson 06 Quiz Pull Request
+
+on:
+  pull_request:
+    branches: [ "main" ]
+    paths:
+      - "lesson_06/quiz/**"
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Use Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: '20.x'
+
+    - name: Build Shared Lib with Node.js
+      working-directory: ./lib/javascript/codedifferently-instructional
+      run: npm ci
+
+    - name: Build Lesson 06 Quiz with Node.js
+      working-directory: ./lesson_06/quiz
+      run: |
+        npm ci
+        npm run check
\ No newline at end of file
diff --git a/.github/workflows/check_push.yml b/.github/workflows/check_push.yml
index 8fb59f86a..5edb6e191 100644
--- a/.github/workflows/check_push.yml
+++ b/.github/workflows/check_push.yml
@@ -8,6 +8,8 @@ on:
       - "lib/**"
       - "lesson_02/quiz/**"
       - "lesson_03/quiz/**"
+      - "lesson_06/quiz/**"
+      - "lesson_06/expression/**"
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -71,3 +73,16 @@ jobs:
         npm ci
         npm run compile
         npm run lint
+
+    - name: Build Lesson 06 Quiz with Node.js
+      working-directory: ./lesson_06/quiz
+      run: |
+        npm ci
+        npm run compile
+        npm run lint
+
+    - name: Build Lesson 06 Expression with Node.js
+      working-directory: ./lesson_06/expression
+      run: |
+        npm ci
+        npm run compile
diff --git a/lesson_06/README.md b/lesson_06/README.md
index cab259851..bdd1cffdb 100644
--- a/lesson_06/README.md
+++ b/lesson_06/README.md
@@ -23,6 +23,7 @@ HW_VERSION=D
 ```
 2. Run the program to determine the expression you must implement.
 ```bash
+npm install
 npm run compile
 npm start
 ```
diff --git a/lesson_06/expression/.env.test b/lesson_06/expression/.env.test
index 56cf4a06f..93aef4eca 100644
--- a/lesson_06/expression/.env.test
+++ b/lesson_06/expression/.env.test
@@ -1 +1 @@
-HW_VERSION=your assigned version here
\ No newline at end of file
+HW_VERSION=F
\ No newline at end of file
diff --git a/lesson_06/expression/src/expression_calculator.ts b/lesson_06/expression/src/expression_calculator.ts
index 76b215c42..0b138ebb7 100644
--- a/lesson_06/expression/src/expression_calculator.ts
+++ b/lesson_06/expression/src/expression_calculator.ts
@@ -1,11 +1,24 @@
 export class ExpressionCalculator {
   /** Returns a calculation involving a, b, c, d, and e */
-  calculate(a: number, b: number, c: number, d: number, e: number): number {
-    // Implement your code here to return the correct value.
-    return 0;
+
+  add(a: number, b: number): number {
+    return a + b;
+  }
+
+  multiply(a: number, b: number): number {
+    return a * b;
+  }
+
+  divide(a: number, b: number): number {
+    if (b === 0) throw new Error("Cannot divide by zero");
+    return a / b;
   }
 
   pow(base: number, exponent: number): number {
     return Math.pow(base, exponent);
   }
+
+  calculate(a: number, b: number, c: number, d: number, e: number): number {
+    return this.multiply(a, this.divide(this.pow(this.add(b, c), d), e));
+  }
 }
diff --git a/lesson_06/expression/src/functions.ts b/lesson_06/expression/src/functions.ts
index ab7433c9c..e193d2f9b 100644
--- a/lesson_06/expression/src/functions.ts
+++ b/lesson_06/expression/src/functions.ts
@@ -1,16 +1,17 @@
-export const FUNCTIONS: Record<string, Function> = Object.freeze({
-  A: (a: number, b: number, c: number, d: number, e: number) =>
-    ((a + b) * c) / Math.pow(d, e),
-  B: (a: number, b: number, c: number, d: number, e: number) =>
-    Math.pow(a + b, c) / (d * e),
-  C: (a: number, b: number, c: number, d: number, e: number) =>
-    a / b + c * Math.pow(d, e),
-  D: (a: number, b: number, c: number, d: number, e: number) =>
-    (a * b) / Math.pow(c + d, e),
-  E: (a: number, b: number, c: number, d: number, e: number) =>
-    Math.pow((a + b) / c, d) * e,
-  F: (a: number, b: number, c: number, d: number, e: number) =>
-    (a * Math.pow(b + c, d)) / e,
-  G: (a: number, b: number, c: number, d: number, e: number) =>
-    ((Math.pow(a, b) + c) * d) / e,
-});
+export const FUNCTIONS: Record<string, (...args: number[]) => number> =
+  Object.freeze({
+    A: (a: number, b: number, c: number, d: number, e: number) =>
+      ((a + b) * c) / Math.pow(d, e),
+    B: (a: number, b: number, c: number, d: number, e: number) =>
+      Math.pow(a + b, c) / (d * e),
+    C: (a: number, b: number, c: number, d: number, e: number) =>
+      a / b + c * Math.pow(d, e),
+    D: (a: number, b: number, c: number, d: number, e: number) =>
+      (a * b) / Math.pow(c + d, e),
+    E: (a: number, b: number, c: number, d: number, e: number) =>
+      Math.pow((a + b) / c, d) * e,
+    F: (a: number, b: number, c: number, d: number, e: number) =>
+      (a * Math.pow(b + c, d)) / e,
+    G: (a: number, b: number, c: number, d: number, e: number) =>
+      ((Math.pow(a, b) + c) * d) / e,
+  });
diff --git a/lesson_06/expression/src/lesson6.test.ts b/lesson_06/expression/src/lesson6.test.ts
index c324ca280..509eb98f5 100644
--- a/lesson_06/expression/src/lesson6.test.ts
+++ b/lesson_06/expression/src/lesson6.test.ts
@@ -17,7 +17,7 @@ describe("Lesson6Test", () => {
     const c = 3;
     const d = 4;
     const e = 5;
-    const expected = FUNCTIONS[process.env.HW_VERSION!].call(
+    const expected = FUNCTIONS[process.env.HW_VERSION || ""].call(
       null,
       ...[a, b, c, d, e],
     );
diff --git a/lesson_06/expression/src/lesson6.ts b/lesson_06/expression/src/lesson6.ts
index bfe71e676..00af72421 100644
--- a/lesson_06/expression/src/lesson6.ts
+++ b/lesson_06/expression/src/lesson6.ts
@@ -13,7 +13,7 @@ const rl = createInterface({
 });
 
 const main = async () => {
-  const testFunction = FUNCTIONS[process.env.HW_VERSION!];
+  const testFunction = FUNCTIONS[process.env.HW_VERSION || ""];
   if (testFunction === undefined) {
     console.log("HW_VERSION version not set in config. Exiting...");
     process.exit(1);
diff --git a/lesson_06/expression/src/utils.ts b/lesson_06/expression/src/utils.ts
index e6f53b6a0..520741a62 100644
--- a/lesson_06/expression/src/utils.ts
+++ b/lesson_06/expression/src/utils.ts
@@ -12,9 +12,9 @@ export const askQuestion = (
   });
 };
 
-export const getFunctionBody = (f: Function) => {
-  const fString = f.toString().split("=>").pop()!;
-  return beautify(fString);
+export const getFunctionBody = (f: () => unknown) => {
+  const fString = f.toString().split("=>").pop();
+  return beautify(fString || "");
 };
 
 export const printFormualaWithValues = (
@@ -34,7 +34,7 @@ export const printFormualaWithValues = (
     ["e", String(e)],
     ["pow", "Math.pow"],
   ).reduce(
-    (acc: string, param: string[]) => acc.replace(param[0]!, param[1]!),
+    (acc: string, param: string[]) => acc.replace(param[0], param[1]),
     functionBody,
   );
   console.log(`\nNow computing the value of ${formula}`);
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 000000000..7ffd06b2c
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,6 @@
+{
+  "name": "code-differently-25-q1-fork",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {}
+}