diff --git a/lesson_06/expression/.env.test b/lesson_06/expression/.env.test
index 56cf4a06f..1eeddbff6 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=B
\ 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..90b1d7a74 100644
--- a/lesson_06/expression/src/expression_calculator.ts
+++ b/lesson_06/expression/src/expression_calculator.ts
@@ -1,11 +1,25 @@
 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;
+    return this.divide(this.pow(this.add(a, b), c), this.multiply(d, e));
   }
 
   pow(base: number, exponent: number): number {
     return Math.pow(base, exponent);
   }
+
+  add(a: number, b: number): number {
+    return a + b;
+  }
+
+  subtract(a: number, b: number): number {
+    return a - b;
+  }
+
+  multiply(a: number, b: number): number {
+    return a * b;
+  }
+  divide(a: number, b: number): number {
+    return a / b;
+  }
 }
diff --git a/lesson_06/stretch_hw/alphaAbbre.js b/lesson_06/stretch_hw/alphaAbbre.js
new file mode 100644
index 000000000..f2a8f2af7
--- /dev/null
+++ b/lesson_06/stretch_hw/alphaAbbre.js
@@ -0,0 +1,47 @@
+function letterToNumber(ch) {
+    return ch.charCodeAt(0) - 96;
+}
+
+function validAbbreviation(word, abbr) {
+    var i = 0; // index for word
+    var j = 0; // index for abbr
+    var lastWasNumber = false;
+    while (j < abbr.length) {
+        var ch = abbr[j];
+        var num1 = letterToNumber(ch);
+        var skipCount = null;
+        if (num1 >= 1 && num1 <= 26) {
+            skipCount = num1;
+            if (j + 1 < abbr.length) {
+                var num2 = letterToNumber(abbr[j + 1]);
+                var combined = num1 * 10 + num2;
+                if (combined >= 10 && combined <= 26) {
+                    skipCount = combined;
+                    j++;
+                }
+            }
+        }
+        if (skipCount !== null && skipCount > 0) {
+            if (lastWasNumber)
+                return false;
+            i += skipCount;
+            if (i > word.length)
+                return false;
+            lastWasNumber = true;
+            j++;
+            continue;
+        }
+        
+        if (i >= word.length || word[i] !== ch) {
+            return false;
+        }
+        i++;
+        j++;
+        lastWasNumber = false;
+    }
+    // Must consume the whole word
+    return i === word.length;
+}
+// Test the function
+console.log(validAbbreviation("internationalization", "i12iz4n"));
+console.log(validAbbreviation("apple", "a2e"));