Add SumCalculator Challenge

SimpleCalculator/SimpleCalculator.iml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

SimpleCalculator/src/SimpleCalculator.java

@@ -0,0 +1,41 @@
+public class SimpleCalculator {
+    private double firstNumber;
+    private double secondNumber;
+
+
+    public double getFirstNumber() {
+        return firstNumber;
+    }
+
+    public double getSecondNumber() {
+        return secondNumber;
+    }
+
+    public void setFirstNumber(double firstNumber) {
+        this.firstNumber = firstNumber;
+    }
+
+    public void setSecondNumber(double secondNumber) {
+        this.secondNumber = secondNumber;
+    }
+
+    public double getAdditionResult() {
+        return firstNumber + secondNumber;
+    }
+
+    public double getSubtractionResult() {
+        return firstNumber - secondNumber;
+    }
+
+    public double getMultiplicationResult() {
+        return firstNumber * secondNumber;
+    }
+
+    public double getDivisionResult() {
+        if (secondNumber == 0) {
+            return 0;
+        } else {
+            return firstNumber / secondNumber;
+        }
+    }
+}