diff --git a/src/userinput.c b/src/userinput.c
index 9e7e51c..98fc020 100644
--- a/src/userinput.c
+++ b/src/userinput.c
@@ -125,6 +125,28 @@ char *gets(char *message, unsigned long *minLength, unsigned long *maxLength) {
     return result;
 }
 
+bool isNumberValid(long double value, long double *min, long double *max, long double *greaterThan, long double *smallerThan, long double leftBorder, long double rightBorder) {
+    if (min != NULL && value < *min) {
+        return false;
+    }
+    if (max != NULL && value > *max) {
+        return false;
+    }
+    if (greaterThan != NULL && !(value > *greaterThan)) {
+        return false;
+    }
+    if (smallerThan != NULL && !(value < *smallerThan)) {
+        return false;
+    }
+    if (value < leftBorder) {
+        return false;
+    }
+    if (value > rightBorder) {
+        return false;
+    }
+    return true;
+}
+
 long double getNumber(char *message, long double *min, long double *max, long double *greaterThan, long double *smallerThan, long double leftBorder, long double rightBorder) {
     while (true) {
         char *input = gets(message, NULL, NULL);
@@ -141,26 +163,7 @@ long double getNumber(char *message, long double *min, long double *max, long do
             continue;
         }
         free(input);
-        bool isValid = true;
-        if (min != NULL && number < *min) {
-            isValid = false;
-        }
-        if (max != NULL && number > *max) {
-            isValid = false;
-        }
-        if (greaterThan != NULL && !(number > *greaterThan)) {
-            isValid = false;
-        }
-        if (smallerThan != NULL && !(number < *smallerThan)) {
-            isValid = false;
-        }
-        if (number < leftBorder) {
-            isValid = false;
-        }
-        if (number > rightBorder) {
-            isValid = false;
-        }
-        if (isValid) {
+        if (isNumberValid(number, min, max, greaterThan, smallerThan, leftBorder, rightBorder)) {
             return number;
         }
         printText("Ungueltige Eingabe! Fuer die eingegebene Zahl muss gelten:");