diff --git a/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java b/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java
index 6196db2..d09674d 100644
--- a/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java
+++ b/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java
@@ -189,7 +189,7 @@ public class Spreadsheet {
 		else if (formula.startsWith("PRODUKT("))  // e.g. PRODUKT(A3:B9)
 			result = "" + pro(formula.substring(8, 10), formula.substring(11, 13));
 		else if (formula.startsWith("MITTELWERT("))  // e.g. MITTELWERT(A3:A5)
-			result = "TODO"; // TODO
+			result = "" + mittelwert(formula.substring(11, 13), formula.substring(14, 16));
 		else if (formula.startsWith("STABW("))  // e.g. STABW(C6:D8) -> Standardabweichung
 			result = "TODO"; // TODO
 		else if (formula.startsWith("MIN("))  // e.g. MIN(C13:H13) -> kleinster Wert
@@ -214,7 +214,6 @@ public class Spreadsheet {
 	 * @return The sum calculated.
 	 */
 	private long sum(String startCellName, String endCellName) {
-		// TODO implement
 		int startCellRow = getRow(startCellName);
 		int startCellCol = getCol(startCellName);
 		int endCellRow = getRow(endCellName);
@@ -294,6 +293,27 @@ public class Spreadsheet {
 		return res;
 	}
 
+	private long mittelwert(String startCellName, String endCellName) {
+		int startCellRow = getRow(startCellName);
+		int startCellCol = getCol(startCellName);
+		int endCellRow = getRow(endCellName);
+		int endCellCol = getCol(endCellName);
+
+		long anzahl = 0;
+
+		long res = 0;
+
+		for (int i = startCellRow; i <= endCellRow; i++) {
+			for (int j = startCellCol; j <= endCellCol; j++) {
+				res = res + (Integer.parseInt(cells[i][j].getValue()));
+				anzahl++;
+			}
+		}
+		res = res/anzahl;
+
+		return res;
+	}
+
 	/**
 	 * This method calculates the result of a "normal" algebraic expression. It only needs to support
 	 * expressions like =B4 or =2+A3-B2, i.e. only with int numbers and other cells and with plus,