diff --git a/bin/.gitignore b/bin/.gitignore
new file mode 100644
index 0000000..2079672
--- /dev/null
+++ b/bin/.gitignore
@@ -0,0 +1,2 @@
+/Spreadsheet.class
+/SpreadsheetTest.class
diff --git a/bin/Spreadsheet.class b/bin/Spreadsheet.class
index 92b411f..6d3f4b5 100644
Binary files a/bin/Spreadsheet.class and b/bin/Spreadsheet.class differ
diff --git a/bin/SpreadsheetTest.class b/bin/SpreadsheetTest.class
index e7086bd..de27e72 100644
Binary files a/bin/SpreadsheetTest.class and b/bin/SpreadsheetTest.class differ
diff --git a/src/Spreadsheet.java b/src/Spreadsheet.java
index e4f120b..8d5088d 100644
--- a/src/Spreadsheet.java
+++ b/src/Spreadsheet.java
@@ -1,18 +1,46 @@
+import java.util.ArrayList;
 
-public class Spreadsheet {
+public class Spreadsheet 
+{
 
-	public String get(String cell) {
-		// to be implemented
-		return null;
+	// the limit of array is hard coded to 128 x 128
+	private String[][] cells = new String[128][128];
+
+	public String get(String cell) 
+	{
+		return cells[0][0];
 	}
 	
-	public void set(String cell, String value) {
-		// to be implemented
+	public void set(String cell, String value) 
+	{
+		cells[0][0] = value;
 	}
 	
-	public String evaluate(String cell) {
-		// to be implemented
-		return null;
+	public String evaluate(String cell) 
+	{
+		String tempCell = cells[0][0];
+		if (tempCell.substring(0,1).equals("-"))
+		{
+			tempCell = tempCell.substring(1);
+		}
+		else if (tempCell.substring(0, 1).equals("'"))
+		{
+			tempCell = tempCell.substring(1);
+			if (tempCell.indexOf('\'') == tempCell.length() - 1)
+			{
+				tempCell = tempCell.substring(0, tempCell.length() - 1);
+				return tempCell;
+			}
+			else
+			{
+				return "#Error";
+			}
+		}
+		if (!tempCell.matches("\\d+"))
+		{
+			return "#Error";
+		}
+		return cells[0][0];
 	}
 	
 }
diff --git a/tests/SpreadsheetTest.java b/tests/SpreadsheetTest.java
index 9e0936a..a82aa10 100644
--- a/tests/SpreadsheetTest.java
+++ b/tests/SpreadsheetTest.java
@@ -4,12 +4,51 @@
 import org.junit.Test;
 
 
-public class SpreadsheetTest {
+public class SpreadsheetTest 
+{
+	Spreadsheet spreadsheet = new Spreadsheet();
 
 	@Test
-	public void test() {
-		fail("Not yet implemented");
-		
+	public void setA1GetMinusOneIntTest() 
+	{
+		spreadsheet.set("A1", "-1");
+		assertSame("Get result doesn't match to the set value", "-1", spreadsheet.get("A1"));
+	}
+	
+	@Test
+	public void setA1EvaluatePlusOneIntTest() 
+	{
+		spreadsheet.set("A1", "1");
+		assertSame("Evaluate result doesn't match to the set value", "1", spreadsheet.evaluate("A1"));
+	}
+	
+	@Test
+	public void setA1EvaluateMinusOneIntTest() 
+	{
+		spreadsheet.set("A1", "-1");
+		assertSame("Evaluate result doesn't match to the set value", "-1", spreadsheet.evaluate("A1"));
+	}
+	
+	@Test
+	public void setA1EvaluateMinusTwoIntTest() 
+	{
+		spreadsheet.set("A1", "-2");
+		assertSame("Evaluate result doesn't match to the set value", "-2", spreadsheet.evaluate("A1"));
+	}
+
+	@Test
+	public void setA1EvaluateA5Test() 
+	{
+		spreadsheet.set("A1", "A5");
+		assertSame("Evaluate result doesn't match to the set value", "#Error", spreadsheet.evaluate("A1"));
+	}
+
+	@Test
+	public void setA1EvaluateCorrectString() 
+	{
+		spreadsheet.set("A1", "'a string'");
+		assertEquals("a string", spreadsheet.evaluate("A1"));
 	}
 
+	
 }