diff --git a/Axel/src/de/hs_mannheim/informatik/spreadsheet/Axel.java b/Axel/src/de/hs_mannheim/informatik/spreadsheet/Axel.java
index df720b3..41c5da2 100644
--- a/Axel/src/de/hs_mannheim/informatik/spreadsheet/Axel.java
+++ b/Axel/src/de/hs_mannheim/informatik/spreadsheet/Axel.java
@@ -11,17 +11,13 @@ public class Axel {
 
 	public static void main(String[] args) throws FileNotFoundException {
 		Spreadsheet spr = new Spreadsheet(10,10);
-		
-		spr.put("A3", "123");
-		spr.put("A2", "1");
-		
-		spr.put("B9", "=41+A2");
-		spr.put("J5", "=7*6");
-		spr.put("J6", "=3/2");
+
+		spr.cells[2][7].setFormula("=5+3");
+		spr.updateSpreadsheet();
+
 		
 		System.out.println(spr);
-		
-		spr.saveCsv("/tmp/test.csv");
+
 		
 		// TODO: You might want to put "UI loop" for entering value and formulas here resp. in some UI methods.
 	}
diff --git a/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java b/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java
index f7877d0..94ddeb5 100644
--- a/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java
+++ b/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java
@@ -210,7 +210,7 @@ public class Spreadsheet {
 	 * @return The result calculated.
 	 */
 	private long calculate(String formula) throws ArithmeticException {
-		Matcher m = Pattern.compile("([A-Z][0-9]*)|[-+*/]|[0-9]*").matcher(formula);
+		Matcher m = Pattern.compile("([A-Z][0-9]*)|[-+*/]|[0-9]+").matcher(formula);
 
 		long res = 0;
 		long currentOperand = 0;
@@ -244,28 +244,27 @@ public class Spreadsheet {
 
 		return res;
 	}
-
 	private long evaluateOperator(long res, long currentOperand, String currentOperator) {
 		switch (currentOperator) {
 			case "+":
-				res += currentOperand;
-				break;
+				return res + currentOperand;
 			case "-":
-				res -= currentOperand;
-				break;
+				return res - currentOperand;
 			case "*":
-				res *= currentOperand;
-				break;
+				return res * currentOperand;
 			case "/":
-				res /= currentOperand;
-				break;
+				return res / currentOperand;
 			default:
 				throw new IllegalArgumentException("Invalid operator: " + currentOperator);
 		}
-		return res;
 	}
 
-	///---
+	///--- ui methods
+	public void updateSpreadsheet() {
+		for (int r = 0; r < cells.length; r++)
+			for (int c = 0; c < cells[r].length; c++)
+				evaluateCell(r, c);
+	}
 	public String toString() {
 		StringBuilder sb = new StringBuilder();