diff --git a/src/main/java/Finance.java b/src/main/java/Finance.java
new file mode 100644
index 00000000..43396959
--- /dev/null
+++ b/src/main/java/Finance.java
@@ -0,0 +1,65 @@
+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(BEST_LOAN_RATES, "usage: bestLoanRates",
+            SAVINGS_CALCULATOR, "usage: savingsCalculator <credits separated by ','> <debits separated by ','>",
+            MORTGAGE_CALCULATOR, "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;
+            default: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) {
+            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..16d3dc80 100644
--- a/src/main/java/com/h2/App.java
+++ b/src/main/java/com/h2/App.java
@@ -12,6 +12,14 @@ public static void main( String[] args )
     }
 
     public static int doubleTheNumber(int number) {
-        return -1;
+        return 2*number;
     }
+
+    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..ee164d52
--- /dev/null
+++ b/src/main/java/com/h2/BestLoanRates.java
@@ -0,0 +1,31 @@
+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 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 (bestRate == 0.0f)
+            System.out.println("No available rates for term: " + loanTermInYears +" years");
+        else
+            System.out.println("Best Available Rate: " + getRates(loanTermInYears) + "%");
+
+    }
+
+    public static float getRates(int loanTermInYears){
+        if (bestRates.containsKey(loanTermInYears)){
+            return bestRates.get(loanTermInYears);
+        }
+        else
+            return 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..3ae80176
--- /dev/null
+++ b/src/main/java/com/h2/MortgageCalculator.java
@@ -0,0 +1,47 @@
+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(){
+        return annualRate/1200;
+    }
+
+    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;
+    }
+
+    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..52bc7e9b
--- /dev/null
+++ b/src/main/java/com/h2/SavingsCalculator.java
@@ -0,0 +1,59 @@
+package com.h2;
+
+import java.time.LocalDate;
+import java.time.YearMonth;
+
+public class SavingsCalculator {
+    private float[] credits;
+    private float[] debits;
+
+    public SavingsCalculator(float[] credits, float[] debits) {
+        this.credits = credits;
+        this.debits = debits;
+    }
+
+    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;
+    }
+
+    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;
+    }
+
+    public float calculate(){
+        return sumOfCredits()-sumOfDebits();
+    }
+
+    public static void main(String[] args){
+        final String[] creditsAsString = args[0].split(",");
+        final String[] debitsAsString = args[1].split(",");
+
+        final float[] credits = new float[creditsAsString.length];
+        final float[] debits = new float[debitsAsString.length];
+
+        for (int i = 0; i < creditsAsString.length; i++) {
+            credits[i] = Utilities.getFloatValue(creditsAsString[i]);
+        }
+
+        for (int i = 0; i < debitsAsString.length; i++) {
+            debits[i] = Utilities.getFloatValue(debitsAsString[i]);
+        }
+
+        final SavingsCalculator calculator = new SavingsCalculator(credits, debits);
+        float netSavings = calculator.calculate();
+        System.out.println("Net Savings = " + netSavings + ", remaining days in month = " + remainingDaysInMonth(LocalDate.now()));
+    }
+}
diff --git a/src/main/java/com/h2/Utilities.java b/src/main/java/com/h2/Utilities.java
new file mode 100644
index 00000000..aaf7c72b
--- /dev/null
+++ b/src/main/java/com/h2/Utilities.java
@@ -0,0 +1,36 @@
+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;
+    }
+}