diff --git a/app/build.gradle b/app/build.gradle
index fbf8721..3cbe5f8 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -31,6 +31,9 @@ dependencies {
     implementation 'androidx.appcompat:appcompat:1.2.0'
     implementation 'androidx.core:core-ktx:1.3.2'
     implementation 'androidx.constraintlayout:constraintlayout:2.0.2'
+    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.1'
+    implementation 'androidx.navigation:navigation-ui-ktx:2.3.1'
+    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test.ext:junit:1.1.2'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
diff --git a/app/src/main/java/com/scainitiative/kotlinscainitiativeproject/MainActivity.kt b/app/src/main/java/com/scainitiative/kotlinscainitiativeproject/MainActivity.kt
index 2ae3088..22b4210 100644
--- a/app/src/main/java/com/scainitiative/kotlinscainitiativeproject/MainActivity.kt
+++ b/app/src/main/java/com/scainitiative/kotlinscainitiativeproject/MainActivity.kt
@@ -2,14 +2,87 @@ package com.scainitiative.kotlinscainitiativeproject
 
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import android.view.View
 import android.view.WindowManager
+import android.widget.Button
+import kotlinx.android.synthetic.main.activity_main.*
 
 class MainActivity : AppCompatActivity() {
 
+    var isOperator = true
+    var numbers = ""
+    var operators = "+"
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
         val w = window;
         w.setFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS, WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS)
     }
+
+    fun numberClicked(view: View) {
+        if (isOperator)
+            displayEdittext.setText("")
+        isOperator = false
+
+        var buttonClicked  =  displayEdittext.text.toString()
+        var buttonSelected  =  view as Button
+        when(buttonSelected.id){
+
+            cal_one.id -> {buttonClicked  += "1"}
+            cal_two.id -> {buttonClicked  += "2"}
+            cal_three.id -> {buttonClicked  += "3"}
+            cal_four.id -> {buttonClicked  += "4"}
+            cal_five.id -> {buttonClicked  += "5"}
+            cal_six.id -> {buttonClicked  += "6"}
+            cal_seven.id -> {buttonClicked  += "7"}
+            cal_eight.id -> {buttonClicked  += "8"}
+            cal_nine.id -> {buttonClicked  += "9"}
+            cal_zero.id -> {buttonClicked  += "0"}
+            cal_full_stop.id -> {buttonClicked  +=  "."}
+            cal_add_minus.id -> {buttonClicked  + "-$buttonClicked"}
+
+        }
+        displayEdittext.setText(buttonClicked)
+
+    }
+
+    fun signOperation(view: View) {
+        isOperator = true
+        numbers = displayEdittext.text.toString()
+        var buttonSelected = view as Button
+        when (buttonSelected.id){
+            cal_minus.id -> operators = "-"
+            cal_divide.id -> operators = "/"
+            cal_multiply.id -> operators = "*"
+            cal_plus.id -> operators = "+"
+        }
+
+
+    }
+
+    fun equalTo(view: View) {
+        var anumber = displayEdittext.text.toString()
+        var result = 0.0
+        when (operators){
+            "+" -> {result = numbers.toDouble() + anumber.toDouble()}
+            "*" -> {result = numbers.toDouble() * anumber.toDouble()}
+            "-" -> {result = numbers.toDouble() - anumber.toDouble()}
+            "/" -> {result = numbers.toDouble() / anumber.toDouble()}
+        }
+        displayEdittext.setText(result.toString())
+
+    }
+
+    fun clear(view: View) {
+        displayEdittext.setText("0")
+        isOperator = true
+    }
+
+    fun percentage(view: View) {
+        var num = displayEdittext.text.toString().toDouble()/100
+        displayEdittext.setText(num.toString())
+        isOperator = true
+
+    }
 }
diff --git a/app/src/main/res/drawable/ic_baseline_arrow_downward_24.xml b/app/src/main/res/drawable/ic_baseline_arrow_downward_24.xml
new file mode 100644
index 0000000..353eabc
--- /dev/null
+++ b/app/src/main/res/drawable/ic_baseline_arrow_downward_24.xml
@@ -0,0 +1,5 @@
+<vector android:height="24dp" android:tint="#261CFF"
+    android:viewportHeight="24" android:viewportWidth="24"
+    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="@android:color/white" android:pathData="M20,12l-1.41,-1.41L13,16.17V4h-2v12.17l-5.58,-5.59L4,12l8,8 8,-8z"/>
+</vector>
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 077f788..f486f63 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -1,65 +1,317 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:fitsSystemWindows="true"
+    android:orientation="vertical"
+    android:background="@color/lightpurple"
     tools:context=".MainActivity">
 
 
-    <ImageView
+    <EditText
+        android:id="@+id/displayEdittext"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:scaleType="centerCrop"
-        android:src="@drawable/main_bg"
-        android:tint="#9F000000" />
+        android:layout_height="270dp"
+        android:layout_marginTop="60dp"
+        android:layout_weight="1"
+        android:background="@color/white"
+        android:ems="10"
+        android:gravity="center|right"
+        android:inputType="number"
+        android:text="@string/_0"
+        android:textSize="40dp"
+        android:paddingEnd="8dp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.0"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
 
     <LinearLayout
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:gravity="center"
-        android:orientation="vertical">
+        android:id="@+id/linearLayout2"
+        android:layout_width="393dp"
+        android:layout_height="233dp"
+        android:layout_marginEnd="8dp"
+        android:layout_marginTop="8dp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/displayEdittext">
 
-        <LinearLayout
+        <TableLayout
             android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:layout_weight="1.2" />
+            android:layout_height="wrap_content"
+            android:layout_weight="1">
 
-        <ImageView
-            android:layout_width="200dp"
-            android:layout_height="200dp"
-            android:contentDescription="@string/sca_logo_description"
-            android:scaleType="centerCrop"
-            android:src="@drawable/sca_icon" />
+            <TableRow
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:layout_marginLeft="6dp">
 
-        <TextView
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:layout_weight="1"
-            android:fontFamily="@font/work_sans_extrabold"
-            android:gravity="center"
-            android:text="@string/track_name"
-            android:textColor="@android:color/white"
-            android:textSize="35sp"
-            android:textStyle="bold" />
-
-        <TextView
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:layout_marginHorizontal="@dimen/twenty_dp"
-            android:layout_weight="1"
-            android:fontFamily="@font/open_sans_bold"
-            android:gravity="center"
-            android:text="@string/welcome_message"
-            android:textColor="@android:color/darker_gray"
-            android:textSize="14sp" />
-
-        <LinearLayout
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:layout_weight="1.2" />
+                <Button
+                    android:id="@+id/cal_C"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/orange"
+                    android:text="@string/c"
+                    android:onClick="clear"
+                    android:textColor="@color/white">
+
+                </Button>
+
+                <Button
+                    android:id="@+id/cal_percent"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/orange"
+                    android:text="@string/percent"
+                    android:onClick="percentage"
+                    android:textColor="@color/white">
+
+                </Button>
+
+                <Button
+                    android:id="@+id/cal_add_minus"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/orange"
+                    android:text="@string/plus_minus"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+
+                </Button>
+
+                <Button
+                    android:id="@+id/cal_divide"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_weight="1"
+                    android:background="@color/orange"
+                    android:text="@string/divide"
+                    android:onClick="signOperation"
+                    android:textColor="@color/white">
+
+                </Button>
+            </TableRow>
+
+            <TableRow
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:layout_marginLeft="6dp"
+                android:paddingTop="10dp">
+
+                <Button
+                    android:id="@+id/cal_seven"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/purple"
+                    android:text="@string/seven"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+                </Button>
+
+                <Button
+                    android:id="@+id/cal_eight"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/purple"
+                    android:text="@string/eight"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+
+                </Button>
+
+                <Button
+                    android:id="@+id/cal_nine"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/purple"
+                    android:text="@string/nine"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+
+                </Button>
+
+                <Button
+                    android:id="@+id/cal_multiply"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_weight="1"
+                    android:background="@color/orange"
+                    android:text="@string/multiply"
+                    android:onClick="signOperation"
+                    android:textColor="@color/white">
+
+                </Button>
+            </TableRow>
+
+            <TableRow
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:layout_marginLeft="6dp"
+                android:layout_marginTop="10dp">
+
+                <Button
+                    android:id="@+id/cal_four"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/purple"
+                    android:text="@string/four"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+
+                </Button>
+
+
+                <Button
+                    android:id="@+id/cal_five"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/purple"
+                    android:text="@string/five"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+
+                </Button>
+
+                <Button
+                    android:id="@+id/cal_six"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/purple"
+                    android:text="@string/six"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+
+                </Button>
+
+
+                <Button
+                    android:id="@+id/cal_minus"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_weight="1"
+                    android:background="@color/orange"
+                    android:text="@string/dot"
+                    android:onClick="signOperation"
+                    android:textColor="@color/white">
+
+                </Button>
+            </TableRow>
+
+            <TableRow
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:layout_marginLeft="6dp"
+                android:layout_marginTop="10dp">
+
+                <Button
+                    android:id="@+id/cal_one"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/purple"
+                    android:text="@string/one"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+
+                </Button>
+
+
+                <Button
+                    android:id="@+id/cal_two"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/purple"
+                    android:text="@string/two"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+
+                </Button>
+
+
+                <Button
+                    android:id="@+id/cal_three"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_marginRight="@dimen/standard"
+                    android:layout_weight="1"
+                    android:background="@color/purple"
+                    android:text="@string/three"
+                    android:onClick="numberClicked"
+                    android:textColor="@color/white">
+
+                </Button>
+
+
+                <Button
+                    android:id="@+id/cal_plus"
+                    android:layout_height="@dimen/maximum"
+                    android:layout_weight="1"
+                    android:background="@color/orange"
+                    android:text="@string/plus"
+                    android:onClick="signOperation"
+                    android:textColor="@color/white">
+
+                </Button>
+            </TableRow>
+        </TableLayout>
     </LinearLayout>
 
+    <LinearLayout
+        android:id="@+id/linearLayout"
+        android:layout_width="394dp"
+        android:layout_height="68dp"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:layout_marginEnd="8dp"
+        android:orientation="horizontal"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/linearLayout2">
+
+
+        <Button
+            android:id="@+id/cal_zero"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginRight="10dp"
+            android:background="@color/purple"
+            android:text="@string/zero"
+            android:onClick="numberClicked"
+            android:textColor="@color/white">
+
+        </Button>
+
+        <Button
+            android:id="@+id/cal_full.stop"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginRight="@dimen/standard"
+            android:background="@color/purple"
+            android:text="@string/full_stop"
+            android:onClick="numberClicked"
+            android:textColor="@color/white">
+
+        </Button>
+
+        <Button
+            android:id="@+id/cal_ans"
+            android:layout_width="195dp"
+            android:layout_height="wrap_content"
+            android:layout_marginRight="8dp"
+            android:background="@color/orange"
+            android:text="@string/equals"
+            android:onClick="equalTo"
+            android:textColor="@color/white">
+
+        </Button>
+    </LinearLayout>
 
-</RelativeLayout>
\ No newline at end of file
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index 030098f..7e4b5c6 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -3,4 +3,8 @@
     <color name="colorPrimary">#6200EE</color>
     <color name="colorPrimaryDark">#3700B3</color>
     <color name="colorAccent">#03DAC5</color>
+    <color name="purple">#9C6BA5</color>
+    <color name="white">#fff</color>
+    <color name="orange">#FDA21B</color>
+    <color name="lightpurple">#CFBCD3</color>
 </resources>
diff --git a/app/src/main/res/values/dimens.xml b/app/src/main/res/values/dimens.xml
index 2655e10..7e8d052 100644
--- a/app/src/main/res/values/dimens.xml
+++ b/app/src/main/res/values/dimens.xml
@@ -1,4 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <dimen name="twenty_dp">20dp</dimen>
+    <dimen name="maximum">50dp</dimen>
+    <dimen name="layout_marginRight">8dp</dimen>
+    <dimen name="standard">15dp</dimen>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 39b53d6..60a4a80 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -3,4 +3,26 @@
     <string name="welcome_message">Hey queen, congratulations on making it into the levelled membership programme being set up by the SCA community. \n\nBut you know you are on the wrong branch right? Head over to your respective level branch and start your project.\n\nWishing you best of luck!!!</string>
     <string name="track_name">SCA Initiative - \nKotlin track</string>
     <string name="sca_logo_description">sca_logo</string>
+    <!-- TODO: Remove or change this placeholder text -->
+    <string name="hello_blank_fragment">Hello blank fragment</string>
+    <string name="_0">0</string>
+    <string name="c">C</string>
+    <string name="percent">%</string>
+    <string name="plus_minus">+/-</string>
+    <string name="divide">/</string>
+    <string name="seven">7</string>
+    <string name="eight">8</string>
+    <string name="nine">9</string>
+    <string name="multiply">*</string>
+    <string name="four">4</string>
+    <string name="five">5</string>
+    <string name="six">6</string>
+    <string name="dot">-</string>
+    <string name="one">1</string>
+    <string name="two">2</string>
+    <string name="three">3</string>
+    <string name="plus">+</string>
+    <string name="zero">0</string>
+    <string name="full_stop">.</string>
+    <string name="equals">=</string>
 </resources>
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index 0eb88fe..41e5cc1 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -8,4 +8,5 @@
         <item name="colorAccent">@color/colorAccent</item>
     </style>
 
+
 </resources>