diff --git a/src/utils/__tests__/calculator.test.ts b/src/utils/__tests__/calculator.test.ts
new file mode 100644
index 0000000..88599e5
--- /dev/null
+++ b/src/utils/__tests__/calculator.test.ts
@@ -0,0 +1,59 @@
+import { add, multiply, divide, subtract } from '../calculator';
+
+describe('Calculator Functions', () => {
+    describe('add()', () => {
+        it('should return the sum of two positive numbers', () => {
+            expect(add(1, 2)).toBe(3);
+        });
+
+        it('should return the sum of a positive and a negative number', () => {
+            expect(add(1, -2)).toBe(-1);
+        });
+
+        it('should return the sum of two negative numbers', () => {
+            expect(add(-1, -2)).toBe(-3);
+        });
+    });
+
+    describe('multiply()', () => {
+        it('should return the product of two positive numbers', () => {
+            expect(multiply(2, 3)).toBe(6);
+        });
+
+        it('should return the product of a positive and a negative number', () => {
+            expect(multiply(2, -3)).toBe(-6);
+        });
+
+        it('should return the product of two negative numbers', () => {
+            expect(multiply(-2, -3)).toBe(6);
+        });
+    });
+
+    describe('divide()', () => {
+        it('should return the quotient of two positive numbers', () => {
+            expect(divide(6, 3)).toBe(2);
+        });
+
+        it('should return the quotient of a positive and a negative number', () => {
+            expect(divide(6, -3)).toBe(-2);
+        });
+
+        it('should handle division by zero', () => {
+            expect(() => divide(6, 0)).toThrowError('Cannot divide by zero');
+        });
+    });
+
+    describe('subtract()', () => {
+        it('should return the difference of two positive numbers', () => {
+            expect(subtract(5, 3)).toBe(2);
+        });
+
+        it('should return the difference of a positive and a negative number', () => {
+            expect(subtract(5, -3)).toBe(8);
+        });
+
+        it('should return the difference of two negative numbers', () => {
+            expect(subtract(-5, -3)).toBe(-2);
+        });
+    });
+});
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diff --git a/src/utils/calculator.ts b/src/utils/calculator.ts
new file mode 100644
index 0000000..891971b
--- /dev/null
+++ b/src/utils/calculator.ts
@@ -0,0 +1,16 @@
+// src/utils/calculator.ts
+export function add(a: number, b: number): number {
+    return a + b;
+}
+
+export function multiply(a: number, b: number): number {
+    return a * b;
+}
+
+export function divide(a: number, b: number): number {
+    return a / b;
+}
+
+export function subtract(a: number, b: number): number {
+    return a - b;
+}
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