diff --git a/src/main/java/core/basesyntax/Calculator.java b/src/main/java/core/basesyntax/Calculator.java
new file mode 100644
index 00000000..7eaf4a60
--- /dev/null
+++ b/src/main/java/core/basesyntax/Calculator.java
@@ -0,0 +1,6 @@
+package core.basesyntax;
+
+public interface Calculator {
+
+    double calculate(double firstNumber, char operationType, double secondNumber);
+}
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/main/java/core/basesyntax/MyCalculator.java b/src/main/java/core/basesyntax/MyCalculator.java
new file mode 100644
index 00000000..1a763dca
--- /dev/null
+++ b/src/main/java/core/basesyntax/MyCalculator.java
@@ -0,0 +1,37 @@
+package core.basesyntax;
+
+public class MyCalculator implements Calculator {
+    private static final char ADDITION = '+';
+    private static final char SUBTRACTION = '-';
+    private static final char DIVISION = '/';
+    private static final char MULTIPLICATION = '*';
+    private static final char RAISING_TO_A_POWER = '^';
+
+    @Override
+    public double calculate(double firstNumber, char operationType, double secondNumber) {
+        switch (operationType) {
+            case ADDITION:
+                return checkResult(firstNumber + secondNumber);
+            case SUBTRACTION:
+                return checkResult(firstNumber - secondNumber);
+            case MULTIPLICATION:
+                return checkResult(firstNumber * secondNumber);
+            case DIVISION:
+                if (secondNumber == 0) {
+                    throw new OperationTypeException("You can't divide by zero");
+                }
+                return checkResult(firstNumber / secondNumber);
+            case RAISING_TO_A_POWER:
+                return checkResult(Math.pow(firstNumber, secondNumber));
+            default:
+                throw new OperationTypeException("This type of operation is not supported");
+        }
+    }
+
+    private double checkResult(double result) {
+        if (result == Double.POSITIVE_INFINITY || result == Double.NEGATIVE_INFINITY) {
+            throw new OperationTypeException("Too large or small value");
+        }
+        return result;
+    }
+}
diff --git a/src/main/java/core/basesyntax/OperationTypeException.java b/src/main/java/core/basesyntax/OperationTypeException.java
new file mode 100644
index 00000000..39706a99
--- /dev/null
+++ b/src/main/java/core/basesyntax/OperationTypeException.java
@@ -0,0 +1,7 @@
+package core.basesyntax;
+
+public class OperationTypeException extends RuntimeException {
+    public OperationTypeException(String message) {
+        super(message);
+    }
+}
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 {
-
-}
diff --git a/src/test/java/core/basesyntax/MyCalculatorTest.java b/src/test/java/core/basesyntax/MyCalculatorTest.java
new file mode 100644
index 00000000..4f98b147
--- /dev/null
+++ b/src/test/java/core/basesyntax/MyCalculatorTest.java
@@ -0,0 +1,274 @@
+package core.basesyntax;
+
+import static java.lang.Double.MAX_VALUE;
+import static java.lang.Double.MIN_VALUE;
+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 MyCalculatorTest {
+    private static final double DELTA = 0.00001;
+    private static final char ADDITION = '+';
+    private static final char SUBTRACTION = '-';
+    private static final char MULTIPLICATION = '*';
+    private static final char DIVISION = '/';
+    private static final char RAISING_TO_A_POWER = '^';
+    private static Calculator myCalculatorTest;
+    private double actual;
+    private double expected;
+
+    @BeforeAll
+    static void beforeAll() {
+        myCalculatorTest = new MyCalculator();
+    }
+
+    @Test
+    void calculate_addPositiveNumbers_Ok() {
+        expected = 155.5;
+        actual = myCalculatorTest.calculate(90.5, ADDITION, 65.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_addNegativeNumbers_Ok() {
+        expected = -241.1;
+        actual = myCalculatorTest.calculate(-177.6, ADDITION, -63.5);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_addPositiveAndNegativeNumbers_Ok() {
+        expected = 136.5;
+        actual = myCalculatorTest.calculate(200.0, ADDITION, -63.5);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_addZeroFirstNumberPosition_Ok() {
+        expected = -77;
+        actual = myCalculatorTest.calculate(0, ADDITION, -77.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_addZeroSecondNumberPosition_Ok() {
+        expected = 200;
+        actual = myCalculatorTest.calculate(200.0, ADDITION, 0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_addMaxValues_NotOk() {
+        assertThrows(OperationTypeException.class, () ->
+                myCalculatorTest.calculate(MAX_VALUE, ADDITION, MAX_VALUE));
+    }
+
+    @Test
+    void calculate_addMinValues_Ok() {
+        expected = 0;
+        actual = myCalculatorTest.calculate(MIN_VALUE, ADDITION, MIN_VALUE);
+        assertEquals(expected, actual, DELTA);
+    }
+
+    @Test
+    void calculate_subtractionPositiveNumbers_Ok() {
+        expected = 25.5;
+        actual = myCalculatorTest.calculate(90.5, SUBTRACTION, 65.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_subtractionNegativeNumbers_Ok() {
+        expected = -114.1;
+        actual = myCalculatorTest.calculate(-177.6, SUBTRACTION, -63.5);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_subtractionPositiveAndNegativeNumbers_Ok() {
+        expected = 263.5;
+        actual = myCalculatorTest.calculate(200.0, SUBTRACTION, -63.5);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_subtractionZeroFirstNumberPosition_Ok() {
+        expected = 77.0;
+        actual = myCalculatorTest.calculate(0, SUBTRACTION, -77.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_subtractionZeroSecondNumberPosition_Ok() {
+        expected = 200;
+        actual = myCalculatorTest.calculate(200.0, SUBTRACTION, 0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_subtractionMaxValues_Ok() {
+        expected = 0;
+        actual = myCalculatorTest.calculate(MAX_VALUE, SUBTRACTION, MAX_VALUE);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_subtractionMinValues_Ok() {
+        expected = 0;
+        actual = myCalculatorTest.calculate(MIN_VALUE, SUBTRACTION, MIN_VALUE);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_multiplicationPositiveNumbers_Ok() {
+        expected = 50.0;
+        actual = myCalculatorTest.calculate(10.0, MULTIPLICATION, 5.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_multiplicationNegativeNumbers_Ok() {
+        expected = 50.0;
+        actual = myCalculatorTest.calculate(-10.0, MULTIPLICATION, -5.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_multiplicationPositiveAndNegativeNumbers_Ok() {
+        expected = -1000.0;
+        actual = myCalculatorTest.calculate(200.0, MULTIPLICATION, -5.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_multiplicationZeroFirstNumberPosition_Ok() {
+        expected = 0;
+        actual = myCalculatorTest.calculate(0, MULTIPLICATION, 77.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_multiplicationZeroSecondNumberPosition_Ok() {
+        expected = 0;
+        actual = myCalculatorTest.calculate(200.0, MULTIPLICATION, 0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_multiplicationMaxValues_NotOk() {
+        assertThrows(OperationTypeException.class, () ->
+                myCalculatorTest.calculate(MAX_VALUE, MULTIPLICATION, MAX_VALUE));
+    }
+
+    @Test
+    void calculate_multiplicationMinValues_Ok() {
+        expected = 0;
+        actual = myCalculatorTest.calculate(MIN_VALUE, MULTIPLICATION, MIN_VALUE);
+        assertEquals(expected, actual, DELTA);
+    }
+
+    @Test
+    void calculate_divisionPositiveNumbers_Ok() {
+        expected = 1.3923;
+        actual = myCalculatorTest.calculate(90.5, DIVISION, 65.0);
+        assertEquals(expected, actual, DELTA);
+    }
+
+    @Test
+    void calculate_divisionNegativeNumbers_Ok() {
+        expected = 4.0;
+        actual = myCalculatorTest.calculate(-20.0, DIVISION, -5.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_divisionPositiveAndNegativeNumbers_Ok() {
+        expected = -4.0;
+        actual = myCalculatorTest.calculate(20.0, DIVISION, -5.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_divisionZeroFirstNumberPosition_Ok() {
+        expected = 0;
+        actual = myCalculatorTest.calculate(0, DIVISION, 77.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_divisionZeroSecondNumberPosition_NotOk() {
+        assertThrows(OperationTypeException.class, () ->
+                myCalculatorTest.calculate(200.0, DIVISION, 0));
+    }
+
+    @Test
+    void calculate_divisionMaxValues_Ok() {
+        expected = 1.0;
+        actual = myCalculatorTest.calculate(MAX_VALUE, DIVISION, MAX_VALUE);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_divisionMinValues_Ok() {
+        expected = 1.0;
+        actual = myCalculatorTest.calculate(MIN_VALUE, DIVISION, MIN_VALUE);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_raisingPositiveValuePositivePower_Ok() {
+        expected = 400.0;
+        actual = myCalculatorTest.calculate(20.0, RAISING_TO_A_POWER, 2.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_raisingNegativeValuePositivePower_Ok() {
+        expected = 400.0;
+        actual = myCalculatorTest.calculate(-20.0, RAISING_TO_A_POWER, 2.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_raisingPositiveValueNegativePower_Ok() {
+        expected = 0.0025;
+        actual = myCalculatorTest.calculate(20.0, RAISING_TO_A_POWER, -2.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_raisingNegativeValueNegativePower_Ok() {
+        expected = 0.0025;
+        actual = myCalculatorTest.calculate(-20.0, RAISING_TO_A_POWER, -2.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_raisingPositiveValueZeroPower_Ok() {
+        expected = 1.0;
+        actual = myCalculatorTest.calculate(20.0, RAISING_TO_A_POWER, 0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_raisingNegativeValueZeroPower_Ok() {
+        expected = 1.0;
+        actual = myCalculatorTest.calculate(-20.0, RAISING_TO_A_POWER, 0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_raisingZeroValuePositivePower_Ok() {
+        expected = 0;
+        actual = myCalculatorTest.calculate(0, RAISING_TO_A_POWER, 2.0);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void calculate_illegalOperation_NotOk() {
+        assertThrows(OperationTypeException.class, () ->
+                myCalculatorTest.calculate(65.0, '!', 50.0));
+    }
+}