diff --git a/.gitignore b/.gitignore
index 070b34e..afc10de 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,5 @@ Java Classes & Interfaces/.DS_Store
 /Java Fundamentals/Java Fundamentals.iml
 /Java Sets/Java Sets.iml
 /Personal/src/tdd/helloworld/pom.xml
+/Personal/src/tdd/hello/world/.idea/
+/Personal/src/tdd/hello/world/HelloWorld.iml
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/Adder.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/Adder.java
similarity index 93%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/Adder.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/Adder.java
index 0901a67..dd219bb 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/Adder.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/Adder.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public class Adder extends CalculateBase implements MathProcessing {
 
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/CalculateBase.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/CalculateBase.java
similarity index 95%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/CalculateBase.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/CalculateBase.java
index 4365590..0944016 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/CalculateBase.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/CalculateBase.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public abstract class CalculateBase {
     private double leftVal;
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/Divider.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/Divider.java
similarity index 87%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/Divider.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/Divider.java
index 03a6e83..fa3aa04 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/Divider.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/Divider.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public class Divider extends CalculateBase {
 
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/DynamicHelper.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/DynamicHelper.java
similarity index 96%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/DynamicHelper.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/DynamicHelper.java
index 4d773d6..ec39711 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/DynamicHelper.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/DynamicHelper.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public class DynamicHelper {
 
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/MathEquation.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/MathEquation.java
similarity index 98%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/MathEquation.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/MathEquation.java
index 1598c7e..08cd54c 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/MathEquation.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/MathEquation.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public class MathEquation {
     private double leftVal;
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/MathOperation.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/MathOperation.java
similarity index 62%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/MathOperation.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/MathOperation.java
index b905a9d..78a0b16 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/MathOperation.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/MathOperation.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public enum MathOperation {
     ADD, SUBTRACT, DIVIDE, MULTIPLY
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/MathProcessing.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/MathProcessing.java
similarity index 85%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/MathProcessing.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/MathProcessing.java
index 37e38db..3ed5572 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/MathProcessing.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/MathProcessing.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public interface MathProcessing {
 
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/Multiplier.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/Multiplier.java
similarity index 88%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/Multiplier.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/Multiplier.java
index 2241bf5..cf3fce2 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/Multiplier.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/Multiplier.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public class Multiplier extends CalculateBase {
 
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/NewCalcEngine.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/NewCalcEngine.java
similarity index 98%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/NewCalcEngine.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/NewCalcEngine.java
index f54ba8f..02737c6 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/NewCalcEngine.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/NewCalcEngine.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 import java.util.Scanner;
 
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/PowerOf.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/PowerOf.java
similarity index 93%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/PowerOf.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/PowerOf.java
index ee189b0..b5da814 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/PowerOf.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/PowerOf.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public class PowerOf implements MathProcessing {
 
diff --git a/Java Classes & Interfaces/src/pluralsite/calculatorengine/Subtractor.java b/Java Classes & Interfaces/src/pluralsite/calculator/engine/Subtractor.java
similarity index 88%
rename from Java Classes & Interfaces/src/pluralsite/calculatorengine/Subtractor.java
rename to Java Classes & Interfaces/src/pluralsite/calculator/engine/Subtractor.java
index b2a51b9..65bf4eb 100644
--- a/Java Classes & Interfaces/src/pluralsite/calculatorengine/Subtractor.java	
+++ b/Java Classes & Interfaces/src/pluralsite/calculator/engine/Subtractor.java	
@@ -1,4 +1,4 @@
-package pluralsite.calculatorengine;
+package pluralsite.calculator.engine;
 
 public class Subtractor extends CalculateBase {
 
diff --git a/Java Fundamentals/src/calculatorengine/CalcEngine.java b/Java Fundamentals/src/calculator/engine/CalcEngine.java
similarity index 99%
rename from Java Fundamentals/src/calculatorengine/CalcEngine.java
rename to Java Fundamentals/src/calculator/engine/CalcEngine.java
index bd8208a..e22c5bb 100644
--- a/Java Fundamentals/src/calculatorengine/CalcEngine.java	
+++ b/Java Fundamentals/src/calculator/engine/CalcEngine.java	
@@ -1,4 +1,4 @@
-package calculatorengine;
+package calculator.engine;
 
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
diff --git a/Java Fundamentals/src/helloworld/HelloWorld.java b/Java Fundamentals/src/hello/world/HelloWorld.java
similarity index 85%
rename from Java Fundamentals/src/helloworld/HelloWorld.java
rename to Java Fundamentals/src/hello/world/HelloWorld.java
index 1dfeed7..705fdb0 100644
--- a/Java Fundamentals/src/helloworld/HelloWorld.java	
+++ b/Java Fundamentals/src/hello/world/HelloWorld.java	
@@ -1,4 +1,4 @@
-package helloworld;
+package hello.world;
 
 public class HelloWorld {
     public static void main(String[] args) {
diff --git a/Java Fundamentals/src/operatorprecedence/OperatorPrecedence.java b/Java Fundamentals/src/operator/precedence/OperatorPrecedence.java
similarity index 92%
rename from Java Fundamentals/src/operatorprecedence/OperatorPrecedence.java
rename to Java Fundamentals/src/operator/precedence/OperatorPrecedence.java
index 370e64a..592c907 100644
--- a/Java Fundamentals/src/operatorprecedence/OperatorPrecedence.java	
+++ b/Java Fundamentals/src/operator/precedence/OperatorPrecedence.java	
@@ -1,4 +1,4 @@
-package operatorprecedence;
+package operator.precedence;
 
 public class OperatorPrecedence {
     public static void main(String[] args) {
diff --git a/Personal/src/tdd/helloworld/lib/hamcrest-core-1.3.jar b/Personal/src/tdd/hello/world/lib/hamcrest-core-1.3.jar
similarity index 100%
rename from Personal/src/tdd/helloworld/lib/hamcrest-core-1.3.jar
rename to Personal/src/tdd/hello/world/lib/hamcrest-core-1.3.jar
diff --git a/Personal/src/tdd/helloworld/lib/junit-4.12.jar b/Personal/src/tdd/hello/world/lib/junit-4.12.jar
similarity index 100%
rename from Personal/src/tdd/helloworld/lib/junit-4.12.jar
rename to Personal/src/tdd/hello/world/lib/junit-4.12.jar
diff --git a/Personal/src/tdd/helloworld/src/main/java/hello/world/Greeting.java b/Personal/src/tdd/hello/world/src/main/java/hello/world/Greeting.java
similarity index 85%
rename from Personal/src/tdd/helloworld/src/main/java/hello/world/Greeting.java
rename to Personal/src/tdd/hello/world/src/main/java/hello/world/Greeting.java
index 7558635..059fa60 100644
--- a/Personal/src/tdd/helloworld/src/main/java/hello/world/Greeting.java
+++ b/Personal/src/tdd/hello/world/src/main/java/hello/world/Greeting.java
@@ -1,4 +1,4 @@
-package tdd.helloworld.src.main.java.hello.world;
+package tdd.hello.world.src.main.java.hello.world;
 
 public class Greeting {
     String message;
diff --git a/Personal/src/tdd/helloworld/src/main/java/hello/world/HelloWorld.java b/Personal/src/tdd/hello/world/src/main/java/hello/world/HelloWorld.java
similarity index 80%
rename from Personal/src/tdd/helloworld/src/main/java/hello/world/HelloWorld.java
rename to Personal/src/tdd/hello/world/src/main/java/hello/world/HelloWorld.java
index a5449df..4bb1db1 100644
--- a/Personal/src/tdd/helloworld/src/main/java/hello/world/HelloWorld.java
+++ b/Personal/src/tdd/hello/world/src/main/java/hello/world/HelloWorld.java
@@ -1,4 +1,4 @@
-package tdd.helloworld.src.main.java.hello.world;
+package tdd.hello.world.src.main.java.hello.world;
 
 /**
  * Hello world!
diff --git a/Personal/src/tdd/helloworld/src/test/java/hello/world/HelloWorldTest.java b/Personal/src/tdd/hello/world/src/test/java/hello/world/HelloWorldTest.java
similarity index 84%
rename from Personal/src/tdd/helloworld/src/test/java/hello/world/HelloWorldTest.java
rename to Personal/src/tdd/hello/world/src/test/java/hello/world/HelloWorldTest.java
index 3b33f1c..27901a2 100644
--- a/Personal/src/tdd/helloworld/src/test/java/hello/world/HelloWorldTest.java
+++ b/Personal/src/tdd/hello/world/src/test/java/hello/world/HelloWorldTest.java
@@ -1,7 +1,7 @@
-package tdd.helloworld.src.test.java.hello.world;
+package tdd.hello.world.src.test.java.hello.world;
 
 import org.junit.Test;
-import tdd.helloworld.src.main.java.hello.world.Greeting;
+import tdd.hello.world.src.main.java.hello.world.Greeting;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
diff --git a/Personal/src/tdd/helloworld/.idea/.gitignore b/Personal/src/tdd/helloworld/.idea/.gitignore
deleted file mode 100644
index 5c98b42..0000000
--- a/Personal/src/tdd/helloworld/.idea/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-# Default ignored files
-/workspace.xml
\ No newline at end of file
diff --git a/Personal/src/tdd/helloworld/.idea/.name b/Personal/src/tdd/helloworld/.idea/.name
deleted file mode 100644
index 8970971..0000000
--- a/Personal/src/tdd/helloworld/.idea/.name
+++ /dev/null
@@ -1 +0,0 @@
-HelloWorld
\ No newline at end of file
diff --git a/Personal/src/tdd/helloworld/.idea/compiler.xml b/Personal/src/tdd/helloworld/.idea/compiler.xml
deleted file mode 100644
index 88d2a10..0000000
--- a/Personal/src/tdd/helloworld/.idea/compiler.xml
+++ /dev/null
@@ -1,16 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="CompilerConfiguration">
-    <annotationProcessing>
-      <profile name="Maven default annotation processors profile" enabled="true">
-        <sourceOutputDir name="target/generated-sources/annotations" />
-        <sourceTestOutputDir name="target/generated-test-sources/test-annotations" />
-        <outputRelativeToContentRoot value="true" />
-        <module name="HelloWorld" />
-      </profile>
-    </annotationProcessing>
-    <bytecodeTargetLevel>
-      <module name="HelloWorld" target="13.0.2" />
-    </bytecodeTargetLevel>
-  </component>
-</project>
\ No newline at end of file
diff --git a/Personal/src/tdd/helloworld/.idea/encodings.xml b/Personal/src/tdd/helloworld/.idea/encodings.xml
deleted file mode 100644
index 63e9001..0000000
--- a/Personal/src/tdd/helloworld/.idea/encodings.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="Encoding">
-    <file url="file://$PROJECT_DIR$/src/main/java" charset="UTF-8" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/Personal/src/tdd/helloworld/.idea/libraries/Maven__junit_junit_4_11.xml b/Personal/src/tdd/helloworld/.idea/libraries/Maven__junit_junit_4_11.xml
deleted file mode 100644
index f33320d..0000000
--- a/Personal/src/tdd/helloworld/.idea/libraries/Maven__junit_junit_4_11.xml
+++ /dev/null
@@ -1,13 +0,0 @@
-<component name="libraryTable">
-  <library name="Maven: junit:junit:4.11">
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/junit/junit/4.11/junit-4.11.jar!/" />
-    </CLASSES>
-    <JAVADOC>
-      <root url="jar://$MAVEN_REPOSITORY$/junit/junit/4.11/junit-4.11-javadoc.jar!/" />
-    </JAVADOC>
-    <SOURCES>
-      <root url="jar://$MAVEN_REPOSITORY$/junit/junit/4.11/junit-4.11-sources.jar!/" />
-    </SOURCES>
-  </library>
-</component>
\ No newline at end of file
diff --git a/Personal/src/tdd/helloworld/.idea/libraries/Maven__org_hamcrest_hamcrest_core_1_3.xml b/Personal/src/tdd/helloworld/.idea/libraries/Maven__org_hamcrest_hamcrest_core_1_3.xml
deleted file mode 100644
index f58bbc1..0000000
--- a/Personal/src/tdd/helloworld/.idea/libraries/Maven__org_hamcrest_hamcrest_core_1_3.xml
+++ /dev/null
@@ -1,13 +0,0 @@
-<component name="libraryTable">
-  <library name="Maven: org.hamcrest:hamcrest-core:1.3">
-    <CLASSES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar!/" />
-    </CLASSES>
-    <JAVADOC>
-      <root url="jar://$MAVEN_REPOSITORY$/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3-javadoc.jar!/" />
-    </JAVADOC>
-    <SOURCES>
-      <root url="jar://$MAVEN_REPOSITORY$/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3-sources.jar!/" />
-    </SOURCES>
-  </library>
-</component>
\ No newline at end of file
diff --git a/Personal/src/tdd/helloworld/.idea/misc.xml b/Personal/src/tdd/helloworld/.idea/misc.xml
deleted file mode 100644
index 70dd4a2..0000000
--- a/Personal/src/tdd/helloworld/.idea/misc.xml
+++ /dev/null
@@ -1,11 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="MavenProjectsManager">
-    <option name="originalFiles">
-      <list>
-        <option value="$PROJECT_DIR$/pom.xml" />
-      </list>
-    </option>
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_13" project-jdk-name="13.0.2" project-jdk-type="JavaSDK" />
-</project>
\ No newline at end of file
diff --git a/Personal/src/tdd/helloworld/.idea/modules.xml b/Personal/src/tdd/helloworld/.idea/modules.xml
deleted file mode 100644
index e3c7927..0000000
--- a/Personal/src/tdd/helloworld/.idea/modules.xml
+++ /dev/null
@@ -1,8 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="ProjectModuleManager">
-    <modules>
-      <module fileurl="file://$PROJECT_DIR$/HelloWorld.iml" filepath="$PROJECT_DIR$/HelloWorld.iml" />
-    </modules>
-  </component>
-</project>
\ No newline at end of file
diff --git a/Personal/src/tdd/helloworld/.idea/vcs.xml b/Personal/src/tdd/helloworld/.idea/vcs.xml
deleted file mode 100644
index c2365ab..0000000
--- a/Personal/src/tdd/helloworld/.idea/vcs.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="VcsDirectoryMappings">
-    <mapping directory="$PROJECT_DIR$/../../.." vcs="Git" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/README.md b/README.md
index fc84c96..118a36b 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,5 @@
 - [Java Fundamentals](https://app.pluralsight.com/library/courses/getting-started-programming-java/table-of-contents)
 - [Java Classes & Interfaces](https://app.pluralsight.com/library/courses/working-classes-interfaces-java/table-of-contents)
 - [Java Collections](https://app.pluralsight.com/library/courses/java-collections-fundamentals/table-of-contents)
+- [Java Sets]()
+- [Java Streams]()