diff --git a/pom.xml b/pom.xml
index c8c1ea3b..757de0cd 100644
--- a/pom.xml
+++ b/pom.xml
@@ -15,7 +15,7 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <maven.compiler.source>11.0.2</maven.compiler.source>
     <maven.compiler.target>11.0.2</maven.compiler.target>
-    <junit.jupiter.version>5.6.2</junit.jupiter.version>
+    <junit.jupiter.version>5.7.2</junit.jupiter.version>
   </properties>
 
   <dependencies>
diff --git a/src/main/java/Finance.java b/src/main/java/Finance.java
new file mode 100644
index 00000000..d8bfb171
--- /dev/null
+++ b/src/main/java/Finance.java
@@ -0,0 +1,64 @@
+import com.h2.BestLoanRates;
+import com.h2.MortgageCalculator;
+import com.h2.SavingsCalculator;
+
+import java.util.Arrays;
+import java.util.Map;
+
+public class Finance {
+    public final static String BEST_LOAN_RATES = "bestLoanRates";
+    public final static String SAVINGS_CALCULATOR = "savingsCalculator";
+    public final static String MORTGAGE_CALCULATOR = "mortgageCalculator";
+
+    public final static Map<String, String> commandsToUsage = Map.of(
+            "bestLoanRates", "usage: bestLoanRates",
+            "savingsCalculator", "usage: savingsCalculator <credits separated by ','> <debits separated by ','>",
+            "mortgageCalculator", "usage: mortgageCalculator <loanAmount> <termInYears> <annualRate>"
+    );
+
+    private static boolean validateCommandArguments(String[] args) {
+        switch (args[0]) {
+            case BEST_LOAN_RATES:
+                return args.length == 1;
+            case SAVINGS_CALCULATOR:
+                return args.length == 3;
+            case MORTGAGE_CALCULATOR:
+                return args.length == 4;
+        }
+        return false;
+    }
+
+    private static void executeCommand(String command, String[] arguments) {
+        switch (command) {
+            case BEST_LOAN_RATES:
+                System.out.println("Finding best loan rates ...");
+                BestLoanRates.main(arguments);
+                return;
+            case SAVINGS_CALCULATOR:
+                System.out.println("Finding your net savings ...");
+                SavingsCalculator.main(arguments);
+                return;
+            case MORTGAGE_CALCULATOR:
+                System.out.println("Finding your monthly payment ...");
+                MortgageCalculator.main(arguments);
+                return;
+        }
+    }
+
+    public static void main(String[] args) {
+        String command = args[0];
+        if (!commandsToUsage.containsKey(command)) {
+            System.out.println(command + ": command not found");
+            return;
+        }
+
+        boolean isValidCommand = validateCommandArguments(args);
+        if (!isValidCommand) {
+            commandsToUsage.get(command);
+            System.out.println(commandsToUsage.get(args[0]));
+            return;
+        }
+
+        executeCommand(command, Arrays.copyOfRange(args, 1, args.length));
+    }
+}
diff --git a/src/main/java/com/h2/App.java b/src/main/java/com/h2/App.java
index 011ff16b..710ca77a 100644
--- a/src/main/java/com/h2/App.java
+++ b/src/main/java/com/h2/App.java
@@ -2,16 +2,21 @@
 
 /**
  * Hello world!
- *
  */
-public class App 
-{
-    public static void main( String[] args )
-    {
-        System.out.println( "Hello World!" );
+public class App {
+    public static void main(String[] args) {
+        System.out.println("Hello World!");
     }
 
     public static int doubleTheNumber(int number) {
-        return -1;
+        return number * 2;
+    }
+
+    private static int add(int[] numbers) {
+        int sum = 0;
+        for (int number : numbers) {
+            sum += number;
+        }
+        return sum;
     }
 }
diff --git a/src/main/java/com/h2/BestLoanRates.java b/src/main/java/com/h2/BestLoanRates.java
new file mode 100644
index 00000000..d6e0e536
--- /dev/null
+++ b/src/main/java/com/h2/BestLoanRates.java
@@ -0,0 +1,29 @@
+package com.h2;
+
+import java.util.Map;
+import java.util.Scanner;
+
+public class BestLoanRates {
+    public static final Map<Integer, Float> bestRates = Map.of(1, 5.50f, 2, 3.45f, 3, 2.67f);
+    public static final float EPSILON = 0.000_000_01f;
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        System.out.println("Enter your name");
+        String name = scanner.nextLine();
+        System.out.println("Hello " + name);
+        System.out.println("Enter the loan term (in years)");
+        int loanTermInYears = scanner.nextInt();
+        float bestRate = getRates(loanTermInYears);
+        if (Math.abs(bestRate - 0.0f) < EPSILON) {
+            System.out.println("No available rates for term: " + loanTermInYears + " years");
+        } else {
+            System.out.println("Best Available Rate: " + getRates(loanTermInYears) + "%");
+        }
+        scanner.close();
+    }
+
+    public static float getRates(int loanTermInYears) {
+        return bestRates.getOrDefault(loanTermInYears, 0.0f);
+    }
+}
diff --git a/src/main/java/com/h2/MortgageCalculator.java b/src/main/java/com/h2/MortgageCalculator.java
new file mode 100644
index 00000000..fbf56768
--- /dev/null
+++ b/src/main/java/com/h2/MortgageCalculator.java
@@ -0,0 +1,52 @@
+package com.h2;
+
+import java.text.DecimalFormat;
+
+public class MortgageCalculator {
+    private long loanAmount;
+    private int termInYears;
+    private float annualRate;
+    private double monthlyPayment;
+
+    public MortgageCalculator(long loanAmount, int termInYears, float annualRate) {
+        this.loanAmount = loanAmount;
+        this.termInYears = termInYears;
+        this.annualRate = annualRate;
+    }
+
+    private int getNumberOfPayments(){
+        return termInYears * 12;
+    }
+
+    private float getMonthlyInterestRate() {
+        float interestRate = annualRate / 100;
+        return interestRate / 12;
+    }
+
+    public void calculateMonthlyPayment() {
+        long P = loanAmount;
+        float r = getMonthlyInterestRate();
+        int n = getNumberOfPayments();
+        double M = P * (((r * Math.pow(1 + r, n))) / ((Math.pow((1 + r), n)) - 1));
+        this.monthlyPayment = M;
+    }
+
+    @Override
+    public String toString() {
+        DecimalFormat df = new DecimalFormat("####0.00");
+        return "monthlyPayment: " + df.format(monthlyPayment);
+    }
+
+    public static void main(String[] args) {
+        long loanAmount = Utilities.getLongValue(args[0]);
+        int termInYears = Utilities.getIntValue(args[1]);
+        float annualRate = Utilities.getFloatValue(args[2]);
+
+        MortgageCalculator calculator = new MortgageCalculator(loanAmount, termInYears, annualRate);
+
+        calculator.calculateMonthlyPayment();
+
+        System.out.println(calculator.toString());
+
+    }
+}
diff --git a/src/main/java/com/h2/SavingsCalculator.java b/src/main/java/com/h2/SavingsCalculator.java
new file mode 100644
index 00000000..5980c8dc
--- /dev/null
+++ b/src/main/java/com/h2/SavingsCalculator.java
@@ -0,0 +1,61 @@
+package com.h2;
+
+import java.time.LocalDate;
+import java.time.YearMonth;
+
+public class SavingsCalculator {
+    private final float[] credits, debits;
+
+    public SavingsCalculator(float[] credits, float[] debits) {
+        this.credits = credits;
+        this.debits = debits;
+    }
+
+    public static void main(String[] args) {
+        String[] creditsAsString = args[0].split(",");
+        String[] debitsAsString = args[1].split(",");
+        float[] credits = new float[creditsAsString.length];
+        for (int i = 0; i < creditsAsString.length; i++) {
+            credits[i] = Float.parseFloat(creditsAsString[i]);
+        }
+        float[] debits = new float[debitsAsString.length];
+        for (int i = 0; i < debitsAsString.length; i++) {
+            debits[i] = Float.parseFloat(debitsAsString[i]);
+        }
+
+        SavingsCalculator calculator = new SavingsCalculator(credits, debits);
+
+        float netSavings = calculator.calculate();
+        System.out.println("Net Savings = "
+                + netSavings
+                + ", remaining days in month = "
+                + remainingDaysInMonth(LocalDate.now()));
+    }
+
+    private static int remainingDaysInMonth(LocalDate date) {
+        YearMonth yearMonth = YearMonth.of(date.getYear(), date.getMonth());
+        int totalDaysInMonth = yearMonth.lengthOfMonth();
+        int remainingDays = totalDaysInMonth - date.getDayOfMonth();
+        return remainingDays;
+    }
+
+    private float sumOfCredits() {
+        float sum = 0.0f;
+        for (float credit : credits) {
+            sum += credit;
+        }
+        return sum;
+    }
+
+    private float sumOfDebits() {
+        float sum = 0.0f;
+        for (float debit : debits) {
+            sum += debit;
+        }
+        return sum;
+    }
+
+    public float calculate() {
+        return sumOfCredits() - sumOfDebits();
+    }
+}
diff --git a/src/main/java/com/h2/Utilities.java b/src/main/java/com/h2/Utilities.java
new file mode 100644
index 00000000..39a56bd3
--- /dev/null
+++ b/src/main/java/com/h2/Utilities.java
@@ -0,0 +1,33 @@
+package com.h2;
+
+public class Utilities {
+    public static long getLongValue(String in) {
+        long out = Long.MIN_VALUE;
+        try {
+            out = Long.parseLong(in);
+        } catch (NumberFormatException e) {
+            throw new IllegalArgumentException(in + " cannot be converted into a 'long' value. Exiting program.");
+        }
+        return out;
+    }
+
+    public static int getIntValue(String in) {
+        int out = Integer.MIN_VALUE;
+        try {
+            out = Integer.parseInt(in);
+        } catch (NumberFormatException e) {
+            throw new IllegalArgumentException(in + " cannot be converted into a 'int' value. Exiting program.");
+        }
+        return out;
+    }
+
+    public static float getFloatValue(String in) {
+        float out = Float.MIN_VALUE;
+        try {
+            out = Float.parseFloat(in);
+        } catch (NumberFormatException e) {
+            throw new IllegalArgumentException(in + " cannot be converted into a 'float' value. Exiting program.");
+        }
+        return out;
+    }
+}