diff --git a/B12NumbersV3/B12NumbersV3.pde b/B12NumbersV3/B12NumbersV3.pde
index 4efd152..7c49f59 100644
--- a/B12NumbersV3/B12NumbersV3.pde
+++ b/B12NumbersV3/B12NumbersV3.pde
@@ -3,7 +3,7 @@
     Beta version of a clock in base 12.
     by Nayan Sawyer
     started Mar 2022
-    version 0.1.4.3 April 30 2022
+    version 0.1.5.0 April 30 2022
     
     Characters are a variation of Kaktovik Inupiaq numerals
     reversed and in base 12 instead of 20. I take no credit 
@@ -11,6 +11,17 @@
     Includes method relay code be Quark - see https://forum.processing.org/two/discussion/13093/how-to-call-function-by-string-content.html
     for more details.
     
+    changelog 0.1.5.0
+    - Quite a few changes by this point. The readme has been 
+    fixed, the button class has gone through many revisions
+    and now allows dynamic calls defined at object creation,
+    the MathPad now works and inputs B12Digits into a 
+    B12Expression, MathDisplay now works and displays the 
+    contents of a B12Expression, and many miscellaneous bugs
+    and inefficiencies have been fixed. I still need to get 
+    better at version numbering, but it is slowly getting 
+    better.
+    
     changelog 0.1.4.0
     - Added MethodRelay code from Quark. Some fixes and 
     changes as well. Condesed some things into fewer files 
@@ -35,22 +46,15 @@ float sMouseY;
 public static final int DECIMAL = 65;
 ClickHandler ch; // Mouse event handler
 
-Clock clock; //<>//
-B12Digit p;
-B12Digit t;
-MathPad m;
+Calculator calc; //<>//
 
 void setup(){
   size(400,400);
   offset = new PVector(width/2, height/2);
   ch = new ClickHandler();
   
-  m = new MathPad(ch,new B12Math());
-  
-  clock = new Clock(new STime48());
-  println("waiting");
-  p = new B12Digit('+');
-  t = new B12Digit('/');
+  calc = new Calculator(ch);
+
 }
 
 void draw(){
@@ -59,12 +63,8 @@ void draw(){
   sMouseY = (mouseY - offset.y)/scale;
   translate(offset.x,offset.y);
   scale(scale);
-  point(0,0);
-  m.display();
-  clock.display();
-  //p.display();
-  t.display();
-  //println( + " " + ;
+  
+  calc.display();
 }
 
 void mouseClicked(){
diff --git a/B12NumbersV3/guiB12Expression.pde b/B12NumbersV3/guiB12Expression.pde
new file mode 100644
index 0000000..73eaf9e
--- /dev/null
+++ b/B12NumbersV3/guiB12Expression.pde
@@ -0,0 +1,28 @@
+class B12Expression {
+  private B12Digit[] expression;
+  
+  B12Expression(){
+    expression = new B12Digit[0];
+  }
+  
+  B12Digit getDigit(int index){ return expression[index]; }
+  int length(){return expression.length;}
+  
+  void setChar(int ind, B12Digit _digit){
+    expression = (B12Digit[])append(expression, _digit); // Add the new digit
+    if(ind < expression.length - 1){ // Swap new digit
+      for(int i = expression.length - 1; i > ind; i--){ // Start at second to last digit
+        expression[i] = expression[i-1]; // Swap object one index below i up into index i
+      }
+      expression[ind] = _digit;
+    }
+  }
+  
+  void addChar(B12Digit _digit){
+    expression = (B12Digit[])append(expression, _digit);
+  }
+  
+  void evaluate(){
+    //TODO set expression to evaluation of expression
+  }
+}
diff --git a/B12NumbersV3/guiB12Math.pde b/B12NumbersV3/guiB12Math.pde
deleted file mode 100644
index 7a96bbd..0000000
--- a/B12NumbersV3/guiB12Math.pde
+++ /dev/null
@@ -1,15 +0,0 @@
-class B12Math {
-  ArrayList <B12Digit> expression;
-  
-  B12Math(){
-    expression = new ArrayList<B12Digit>();;
-  }
-  
-  void delete(int pos){
-    expression.remove(pos);
-  }
-  
-  void evaluate(){
-    //TODO set expression to evaluation of expression
-  }
-}
diff --git a/B12NumbersV3/guiCalculator.pde b/B12NumbersV3/guiCalculator.pde
new file mode 100644
index 0000000..00c520e
--- /dev/null
+++ b/B12NumbersV3/guiCalculator.pde
@@ -0,0 +1,16 @@
+class Calculator{
+  B12Expression ex;
+  MathPad m;
+  MathDisplay d;
+  
+  Calculator(ClickHandler _ch){
+    ex = new B12Expression();
+    m = new MathPad(_ch,ex);
+    d = new MathDisplay(ex);
+  }
+  
+  void display(){
+    m.display();
+    d.display();
+  }
+}
diff --git a/B12NumbersV3/guiMathDisplay.pde b/B12NumbersV3/guiMathDisplay.pde
index b321f9e..8bade12 100644
--- a/B12NumbersV3/guiMathDisplay.pde
+++ b/B12NumbersV3/guiMathDisplay.pde
@@ -1,14 +1,24 @@
-class MathDisplay{
-  B12Math math;
+class MathDisplay {
+  PVector pos;
+  B12Expression ex;
   
-  MathDisplay(B12Math _math){
-    math = _math;
+  MathDisplay(B12Expression _ex){
+    ex = _ex;
+    pos = new PVector(0,0);
   }
   
-  // TODO take expression from math and display it in whatever state it is in
+  PVector getPos(){ return pos; }
+  void setPos(PVector _pos){ pos = _pos; }
+  
   void display(){
-    for(int i = 0; i < math.expression.size(); i++){
-      
+    pushMatrix();
+    translate(pos.x,pos.y);
+    int count = 0;
+    for(int i = ex.length() - 1; i >= 0 ; i--){
+      ex.getDigit(i).setRefPos((-12 * (count+1)), 0);
+      ex.getDigit(i).display();
+      count++;
     }
+    popMatrix();
   }
 }
diff --git a/B12NumbersV3/guiMathPad.pde b/B12NumbersV3/guiMathPad.pde
index 05154cb..554b24f 100644
--- a/B12NumbersV3/guiMathPad.pde
+++ b/B12NumbersV3/guiMathPad.pde
@@ -1,11 +1,11 @@
 class MathPad{
-  B12Math math;
+  B12Expression ex;
   ClickHandler ch;
   B12Button[] buttons;
   PVector pos;
   
-  MathPad(ClickHandler _ch, B12Math _math){
-    math = _math;
+  MathPad(ClickHandler _ch, B12Expression _ex){
+    ex = _ex;
     ch = _ch;
     pos = new PVector(0,0);
     buttons = new B12Button[12];
@@ -19,15 +19,12 @@ class MathPad{
       buttons[i].setColor(220,150);
     }
   }
-  // DONE draw a grid for buttons
-  // DONE draw characters in grid
-  // DONE detect mousepresses on the buttons (maybe a global mouse handler?)
-  // TODO send characters to math
+
+  // TODO send characters to display
   
-  void addChar(B12Digit digit){
-    //math.addChar(digit);
-    //math.expression.add(new B12Char('/'));
-    println("clicked " + digit.getValue());
+  void addChar(B12Digit _digit){
+    ex.addChar(_digit);
+    println("clicked " + _digit.getValue());
   }
   
   void display(){