diff --git a/.classpath b/.classpath
new file mode 100644
index 0000000..3e0fb27
--- /dev/null
+++ b/.classpath
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.junit.JUNIT_CONTAINER/4"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>
diff --git a/src/debug/ContainerArray.java b/src/debug/ContainerArray.java
index 124ece6..9f90873 100755
--- a/src/debug/ContainerArray.java
+++ b/src/debug/ContainerArray.java
@@ -2,7 +2,7 @@
 
 
 public class ContainerArray<E> {
-    private int initialCapacity = 10;
+    private int limit = 10;
     private int currentSize = 0;
     private Object[] internalArray;
 
@@ -11,11 +11,12 @@ public ContainerArray () {
     }
 
     public ContainerArray (int initialCapacity) {
-        internalArray = new Object[initialCapacity];
+        internalArray = new Object[limit];
     }
 
     public void add (E element) {
-        internalArray[currentSize++] = element;
+        if (currentSize == limit) return;
+    	internalArray[currentSize++] = element;
     }
 
     public int size () {
@@ -23,11 +24,22 @@ public int size () {
     }
 
     public void remove (E objectToRemove) {
-        currentSize--;
+    	currentSize--;
+    	
+    	int i = 0;
+    	while (!internalArray[i].equals(objectToRemove)) {
+    		i++;
+    	}
+    	if (i < currentSize) {
+    		for (int k = i; k < currentSize; k++) {
+    			internalArray[k] = internalArray[k+1];
+    		}
+    	}
+    	internalArray[currentSize] = null;
     }
 
     @SuppressWarnings("unchecked")
     public E get (int index) {
         return (E)internalArray[index];
     }
-}
+}
\ No newline at end of file
diff --git a/src/debug/ContainerArrayTest.java b/src/debug/ContainerArrayTest.java
index c566d50..5524644 100755
--- a/src/debug/ContainerArrayTest.java
+++ b/src/debug/ContainerArrayTest.java
@@ -43,5 +43,18 @@ public void testObjectIsRemoved () {
         myContainer.add("Bear");
         myContainer.remove("Bear");
         assertEquals("Remove should be same reference", alligator, myContainer.get(0));
+        myContainer.remove("Alligator");
+        assertEquals(null, myContainer.get(0));
+    }
+    
+    @Test
+    public void testSizeLimit() {
+    	for (int i = 0; i < 11; i++) {
+    		myContainer.add("Yo");
+    	}
+    	assertEquals(10, myContainer.size());
     }
+    
 }
+
+
diff --git a/src/tdd/Sheet.java b/src/tdd/Sheet.java
new file mode 100644
index 0000000..a73b537
--- /dev/null
+++ b/src/tdd/Sheet.java
@@ -0,0 +1,50 @@
+package tdd;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class Sheet {
+	
+	private Map<String, String> mySheet;
+	
+	public Sheet(){
+		mySheet = new HashMap<String, String>();
+	}
+	
+	public String get(String string) {
+		// TODO Auto-generated method stub
+		String val = mySheet.get(string);
+		if(val == null){
+			return "";
+		}
+		return strip(val);
+	}
+
+	public void put(String theCell, String string) {
+		// TODO Auto-generated method stub
+		mySheet.put(theCell, string);
+	}
+	
+	private String strip(String string){
+		if(isNumeric(string)){
+			return string.trim();
+		}
+		return string;
+	}
+	
+	private boolean isNumeric(String s) {  
+	    return s.matches("\\s+[-+]?\\d+\\.?\\d+\\s+");
+	}
+
+	public Object getLiteral(String theCell) {
+		// TODO Auto-generated method stub
+		String val = mySheet.get(theCell);
+		if(val == null){
+			return "";
+		}
+		return val;
+	}
+	
+
+}
+
diff --git a/src/tdd/TestSheet.java b/src/tdd/TestSheet.java
new file mode 100644
index 0000000..a0bbe84
--- /dev/null
+++ b/src/tdd/TestSheet.java
@@ -0,0 +1,85 @@
+package tdd;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+public class TestSheet {
+
+	@Test
+	public void testThatCellsAreEmptyByDefault() {
+		Sheet sheet = new Sheet();
+		assertEquals("", sheet.get("A1"));
+		assertEquals("", sheet.get("ZX347"));
+	}
+
+	@Test
+	public void testThatTextCellsAreStored() {
+		Sheet sheet = new Sheet();
+		String theCell = "A21";
+
+		sheet.put(theCell, "A string");
+		assertEquals("A string", sheet.get(theCell));
+
+		sheet.put(theCell, "A different string");
+		assertEquals("A different string", sheet.get(theCell));
+
+		sheet.put(theCell, "");
+		assertEquals("", sheet.get(theCell));
+	}
+
+	@Test
+	public void testThatManyCellsExist() {
+		Sheet sheet = new Sheet();
+		sheet.put("A1", "First");
+		sheet.put("X27", "Second");
+		sheet.put("ZX901", "Third");
+
+		assertEquals("A1", "First", sheet.get("A1"));
+		assertEquals("X27", "Second", sheet.get("X27"));
+		assertEquals("ZX901", "Third", sheet.get("ZX901"));
+
+		sheet.put("A1", "Fourth");
+		assertEquals("A1 after", "Fourth", sheet.get("A1"));
+		assertEquals("X27 same", "Second", sheet.get("X27"));
+		assertEquals("ZX901 same", "Third", sheet.get("ZX901"));
+	}
+
+	@Test
+	public void testThatNumericCellsAreIdentifiedAndStored() {
+		Sheet sheet = new Sheet();
+		String theCell = "A21";
+
+		sheet.put(theCell, "X99"); // "Obvious" string
+		assertEquals("X99", sheet.get(theCell));
+
+		sheet.put(theCell, "14"); // "Obvious" number
+		assertEquals("14", sheet.get(theCell));
+
+		sheet.put(theCell, " 99 X"); // Whole string must be numeric
+		assertEquals(" 99 X", sheet.get(theCell));
+
+		sheet.put(theCell, " 1234 "); // Blanks ignored
+		assertEquals("1234", sheet.get(theCell));
+
+		sheet.put(theCell, " "); // Just a blank
+		assertEquals(" ", sheet.get(theCell));
+	}
+	
+	@Test
+	public void testThatWeHaveAccessToCellLiteralValuesForEditing() { 
+		  Sheet sheet = new Sheet();
+		  String theCell = "A21";
+
+		  sheet.put(theCell, "Some string"); 
+		  assertEquals("Some string", sheet.getLiteral(theCell));
+
+		  sheet.put(theCell, " 1234 "); 
+		  assertEquals(" 1234 ", sheet.getLiteral(theCell));
+
+		  sheet.put(theCell, "=7"); // Foreshadowing formulas:)
+		  assertEquals("=7", sheet.getLiteral(theCell));
+		}
+
+
+}