diff --git a/src/main/java/core/basesyntax/Calculator.java b/src/main/java/core/basesyntax/Calculator.java
new file mode 100644
index 00000000..baaf8e27
--- /dev/null
+++ b/src/main/java/core/basesyntax/Calculator.java
@@ -0,0 +1,23 @@
+package core.basesyntax;
+
+public class Calculator {
+    public double calculate(double first, double second, char operation) {
+        switch (operation) {
+            case '+':
+                return first + second;
+            case '-':
+                return first - second;
+            case '*':
+                return first * second;
+            case '^':
+                return Math.pow(first, second);
+            case '/':
+                if (second == 0) {
+                    throw new ArithmeticException("Can't divide by zero");
+                }
+                return first / second;
+            default:
+                throw new IllegalArgumentException("Invalid operation");
+        }
+    }
+}
diff --git a/src/main/java/core/basesyntax/HelloWorld.java b/src/main/java/core/basesyntax/HelloWorld.java
deleted file mode 100644
index 97db782b..00000000
--- a/src/main/java/core/basesyntax/HelloWorld.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package core.basesyntax;
-
-/**
- * Feel free to remove this class and create your own.
- */
-public class HelloWorld {
-
-}
diff --git a/src/test/java/core/basesyntax/CalculatorTest.java b/src/test/java/core/basesyntax/CalculatorTest.java
new file mode 100644
index 00000000..edae83f5
--- /dev/null
+++ b/src/test/java/core/basesyntax/CalculatorTest.java
@@ -0,0 +1,296 @@
+package core.basesyntax;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+class CalculatorTest {
+    private static Calculator calculator;
+
+    @BeforeAll
+    static void beforeAll() {
+        calculator = new Calculator();
+    }
+
+    @Test
+    void addictionTwoPositive() {
+        double first = 7;
+        double second = 14;
+        double expected = 21;
+        double actual = calculator.calculate(first, second, '+');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void addictionTwoNegative() {
+        double first = -38;
+        double second = -17;
+        double expected = -55;
+        double actual = calculator.calculate(first, second, '+');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void addictionPositiveAndNegative() {
+        double first = 40;
+        double second = -20;
+        double expected = 20;
+        double actual = calculator.calculate(first, second, '+');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void addictionZero() {
+        double first = 0;
+        double second = 93;
+        double expected = 93;
+        double actual = calculator.calculate(first, second, '+');
+        assertEquals(expected, actual);
+        first = 36;
+        second = 0;
+        expected = 36;
+        actual = calculator.calculate(first, second, '+');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void addictionMaxValue() {
+        double first = Double.MAX_VALUE;
+        double second = -7;
+        double expected = Double.MAX_VALUE;
+        double actual = calculator.calculate(first, second, '+');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void addictionMinValue() {
+        double first = Double.MIN_VALUE;
+        double second = 0;
+        double expected = Double.MIN_VALUE;
+        double actual = calculator.calculate(first, second, '+');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void subtractionTwoPositive() {
+        double first = 15;
+        double second = 10;
+        double expected = 5;
+        double actual = calculator.calculate(first, second, '-');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void subtractionTwoNegative() {
+        double first = -3;
+        double second = -4;
+        double expected = 1;
+        double actual = calculator.calculate(first, second, '-');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void subtractionPositiveAndNegative() {
+        double first = 34;
+        double second = -14;
+        double expected = 48;
+        double actual = calculator.calculate(first, second, '-');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void subtractionZero() {
+        double first = 0;
+        double second = -17;
+        double expected = 17;
+        double actual = calculator.calculate(first, second, '-');
+        assertEquals(expected, actual);
+        first = -11;
+        second = 0;
+        expected = -11;
+        actual = calculator.calculate(first, second, '-');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void subtractionMaxValue() {
+        double first = Double.MAX_VALUE;
+        double second = -4;
+        double expected = Double.MAX_VALUE;
+        double actual = calculator.calculate(first, second, '-');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void subtractionMinValue() {
+        double first = Double.MIN_VALUE;
+        double second = 3;
+        double expected = -3;
+        double actual = calculator.calculate(first, second, '-');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void multiplicationTwoPositive() {
+        double first = 6;
+        double second = 4;
+        double expected = 24;
+        double actual = calculator.calculate(first, second, '*');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void multiplicationTwoNegative() {
+        double first = -7;
+        double second = -14;
+        double expected = 98;
+        double actual = calculator.calculate(first, second, '*');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void multiplicationPositiveAndNegative() {
+        double first = 7;
+        double second = -21;
+        double expected = -147;
+        double actual = calculator.calculate(first, second, '*');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void multiplicationZero() {
+        double first = 0;
+        double second = 346;
+        double expected = 0;
+        double actual = calculator.calculate(first, second, '*');
+        assertEquals(expected, actual);
+        first = 52;
+        second = 0;
+        expected = 0;
+        actual = calculator.calculate(first, second, '*');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void multiplicationMaxValue() {
+        double first = Double.MAX_VALUE;
+        double second = 32;
+        double expected = Double.POSITIVE_INFINITY;
+        double actual = calculator.calculate(first, second, '*');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void multiplicationMinValue() {
+        double first = Double.MIN_VALUE;
+        double second = 3;
+        double expected = 1.5E-323;
+        double actual = calculator.calculate(first, second, '*');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void divisionTwoPositive() {
+        double first = 6;
+        double second = 2;
+        double expected = 3;
+        double actual = calculator.calculate(first, second, '/');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void divisionTwoNegative() {
+        double first = -10;
+        double second = -5;
+        double expected = 2;
+        double actual = calculator.calculate(first, second, '/');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void divisionPositiveAndNegative() {
+        double first = 20;
+        double second = -5;
+        double expected = -4;
+        double actual = calculator.calculate(first, second, '/');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void divisionZero() {
+        double first = 0;
+        double second = 300;
+        double expected = 0;
+        double actual = calculator.calculate(first, second, '/');
+        assertEquals(expected, actual);
+        double firstL = 35437;
+        double secondL = 0;
+        assertThrows(ArithmeticException.class, () -> {
+            calculator.calculate(firstL, secondL, '/');
+        });
+    }
+
+    @Test
+    void divisionMaxValue() {
+        double first = Double.MAX_VALUE;
+        double second = 7;
+        double expected = 2.5681330498033083E307;
+        double actual = calculator.calculate(first, second, '/');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void divisionMinValue() {
+        double first = Double.MIN_VALUE;
+        double second = 3;
+        double expected = 0;
+        double actual = calculator.calculate(first, second, '/');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void raiseToPower() {
+        double first = 7;
+        double second = 3;
+        double expected = 343;
+        double actual = calculator.calculate(first, second, '^');
+        assertEquals(expected, actual);
+        first = -7;
+        second = 3;
+        expected = -343;
+        actual = calculator.calculate(first, second, '^');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void raiseToNegativePower() {
+        double first = 7;
+        double second = -1;
+        double expected = 0.14285714285714285;
+        double actual = calculator.calculate(first, second, '^');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void raiseToZeroPower() {
+        double first = 4363;
+        double second = 0;
+        double expected = 1;
+        double actual = calculator.calculate(first, second, '^');
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void checkOperation() {
+        double first = 7;
+        double second = 4;
+        assertThrows(IllegalArgumentException.class, () -> {
+            calculator.calculate(first, second, '!');
+        });
+        assertThrows(IllegalArgumentException.class, () -> {
+            calculator.calculate(first, second, '3');
+        });
+    }
+}
diff --git a/src/test/java/core/basesyntax/HelloWorldTest.java b/src/test/java/core/basesyntax/HelloWorldTest.java
deleted file mode 100644
index 9a90d822..00000000
--- a/src/test/java/core/basesyntax/HelloWorldTest.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package core.basesyntax;
-
-/**
- * Feel free to remove this class and create your own.
- */
-public class HelloWorldTest {
-
-}