diff --git a/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java b/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java
index 511d338..a458548 100644
--- a/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java
+++ b/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java
@@ -397,7 +397,7 @@ public class Spreadsheet {
 	 * @param formula The expression to be evaluated.
 	 * @return The result calculated.
 	 */
-	private long calculate(String formula) throws ArithmeticException {
+	public long calculate(String formula) throws ArithmeticException {
 		Matcher m = Pattern.compile("([A-Z][0-9]*)|[-\\+\\*/]|[0-9]*").matcher(formula);
 
 		long res = 0;