public void onClick(View v) {

        // display is assumed to be the TextView used for the Calculator display
        String currDisplayValue = display.getText().toString();

        Button b = (Button)v;  // We assume only buttons have onClickListeners for this App
        String label = b.getText().toString();  // read the label on the button clicked

        switch (v.getId())
        {
            case R.id.clear:
                calc.clear();
               display.setText("");
                //v.clear();
                break;
            case R.id.plus:
            case R.id.minus:
            case R.id.mult:
            case R.id.div:
                String operator = label;
                display.setText("");
                calc.update(operator, currDisplayValue);

                break;
            case R.id.equals:
              display.setText(calc.equalsCalculation(currDisplayValue));
                break;

            case R.id.backSpace:
                // Do whatever you need to do when the back space button is pressed
                //Removes the right most character ex: if you had the number 12 and pressed this button
                //it would remove the 2. Must take the existing string, remove the last character and
                //pass the new string into the display.

                display.setText(currDisplayValue);
                break;
            default:
                // If the button isn't one of the above, it must be a digit
                String digit = label;// This is the digit pressed
                display.append(digit);
                break;
        }
    }

NumberEntered = NumberEntered.substring(0, NumberEntered.length() - 1);