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..c6ff102 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..fadfe84 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..d12df52 100644
--- a/src/Spreadsheet.java
+++ b/src/Spreadsheet.java
@@ -1,18 +1,128 @@
 
 public class Spreadsheet {
+	String [][] sheet = new String [20][20];
+	String [] abcd = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T"};
 
 	public String get(String cell) {
-		// to be implemented
-		return null;
+		String letter = cell.substring(0, 1);
+		String column = cell.substring(1, 2);
+		int columnNumber, rowNumber;
+		
+		rowNumber = searchCellRow(letter);
+		columnNumber = searchCellColumn(column);
+		
+		return sheet[rowNumber][columnNumber];
+	}
+
+	private int searchCellColumn(String column) {
+		boolean found = false;
+		int counter = 0;
+		while (!found && counter < 20) {
+			if (column.equals(String.valueOf(counter))) {
+				found = true;
+			}
+			else {
+				++counter;
+			}
+		}
+		return counter;
+	}
+
+	private int searchCellRow(String letter) {
+		boolean found = false;
+		int counter = 0;
+		
+		while (!found && counter < 20) {
+			if (letter.equals(abcd[counter])) {
+				found = true;
+			}
+			else {
+				++counter;
+			}
+		}
+		return counter;
 	}
 	
 	public void set(String cell, String value) {
-		// to be implemented
+		String letter = cell.substring(0, 1);
+		String column = cell.substring(1, 2);
+		
+		sheet[searchCellRow(letter)][searchCellColumn(column)] = value;
 	}
 	
 	public String evaluate(String cell) {
-		// to be implemented
+		String value = get(cell);
+		for (int i = 0; i < value.length(); i++) {
+			if ((value.charAt(i) == '+') || (value.charAt(i) == '-') || (value.charAt(i) == '*') || (value.charAt(i) == '/')) {
+				return calculator(value);
+			}
+		}
+		if (value.charAt(0) == '=') {
+			if ((Character.isAlphabetic(value.charAt(1)) && (Character.isDigit(value.charAt(2))))) {
+				String refCell = value.substring(1, 3);
+				String circular = "=" + cell;
+				if (get(refCell) != circular) {
+					return get(refCell);
+				}
+				else {
+					return "#Circular";
+				}
+			}
+			String realValue = "";
+			for (int i = 1; i < value.length(); i++) {
+				realValue = realValue + value.charAt(i);
+			}
+			value = realValue;
+		}
+		
+		if (isANumber(value)) {
+			return value;
+		}
+		else if (isAString(value)) {
+			String realString = "";
+			for (int i = 1; i < value.length() - 1; i++) {
+				realString = realString + value.charAt(i);
+			}
+			return realString;
+		}
+		else {
+			return "#Error";
+		}
+	}
+
+	private String calculator(String value) {
+		int calc;
 		return null;
 	}
+
+	private boolean isAString(String value) {
+		if ((value.charAt(0) == '\'') && (value.charAt(value.length() - 1) == '\'')){
+			return true;
+		}
+		else {
+			return false;
+		}
+	}
+
+	private Boolean isANumber(String value) {
+		int counter = 0;
+		if (value.isEmpty()) {
+			return false;
+		}
+		if (value.charAt(counter) == '-') {
+			if (value.length() > 1) {
+				++counter;
+			}
+			else {
+				return false;
+			}
+		}
+		for (; counter < value.length(); ++counter) {
+			if (!Character.isDigit(value.charAt(counter))) {
+				return false;
+			}
+		}
+		return true;
+	}
 	
 }
diff --git a/tests/SpreadsheetTest.java b/tests/SpreadsheetTest.java
index 9e0936a..32c601c 100644
--- a/tests/SpreadsheetTest.java
+++ b/tests/SpreadsheetTest.java
@@ -5,11 +5,72 @@
 
 
 public class SpreadsheetTest {
+	Spreadsheet sheet = new Spreadsheet();
 
-	@Test
-	public void test() {
-		fail("Not yet implemented");
-		
+	@Test public void testSetA4_12() {
+		String cell = "A4";
+		sheet.set(cell, "12");
+		assertEquals("12", sheet.get(cell));
 	}
+	
+	@Test public void testSetB12_4() {
+		String cell = "B12";
+		sheet.set(cell, "4");
+		assertEquals("4", sheet.get(cell));
+	}
+	
+	@Test public void evaluateString_StringWithQuotes() {
+		String cell = "B12";
+		sheet.set(cell, "'thisIsAString'");
+		assertEquals("thisIsAString", sheet.evaluate(cell));
+	}
+	@Test public void evaluateUnquotedString_Error() {
+		String cell = "A1";
+		sheet.set(cell, "'thisIsNotAString");
+		assertEquals("#Error", sheet.evaluate(cell));
+	}
+	@Test public void evaluateInvalidNumber_Error() {
+		String cell = "A1";
+		sheet.set(cell, "324as");
+		assertEquals("#Error", sheet.evaluate(cell));
+	}
+	@Test public void evaluateNegativeNumber_minus10() {
+		String cell = "F2";
+		sheet.set(cell, "-10");
+		assertEquals("-10", sheet.evaluate(cell));
+	}
+	@Test public void evaluateStringEquals_StringWithoutEqual() {
+		String cell = "D9";
+		sheet.set(cell, "='thisIsAString'");
+		assertEquals("thisIsAString", sheet.evaluate(cell));
+	}
+	@Test public void evaluateNumberEquals_NumberWithoutEqual() {
+		String cell = "C5";
+		sheet.set(cell, "=-15");
+		assertEquals("-15", sheet.evaluate(cell));
+	}
+	@Test public void evaluateStringEqualsWithError_Error() {
+		String cell = "C5";
+		sheet.set(cell, "=='thisIsAString");
+		assertEquals("#Error", sheet.evaluate(cell));
+	}
+	@Test public void evaluateRefCell_valueInF2() {
+		String cell = "C5";
+		sheet.set(cell, "=F2");
+		assertEquals(sheet.get("F2"), sheet.evaluate(cell));
+	}
+	@Test public void evaluateIncorrectRefCell_Error() {
+		String cell = "C6";
+		sheet.set(cell, "=2F");
+		assertEquals("#Error", sheet.evaluate(cell));
+	}
+	@Test public void evaluateCircularRefCell_Circular() {
+		String cell = "F2";
+		sheet.set("C5", "=F2");
+		sheet.set(cell, "=C5");
+		assertEquals("#Circular", sheet.evaluate(cell));
+	}
+	
+	
 
 }