diff --git a/reasoning_gym/arithmetic/chain_sum.py b/reasoning_gym/arithmetic/chain_sum.py
index 2a3f6b7a..0dccad1f 100644
--- a/reasoning_gym/arithmetic/chain_sum.py
+++ b/reasoning_gym/arithmetic/chain_sum.py
@@ -56,7 +56,11 @@ class ChainSum:
         num_terms = item_rng.randint(self.config.min_terms, self.config.max_terms)
         num_digits = item_rng.randint(self.config.min_digits, self.config.max_digits)
         
-        expression, result = self._generate_task(item_rng, num_terms, num_digits)
+        # Calculate value ranges based on number of digits
+        min_value = 10 ** (num_digits - 1)  # e.g., 100 for 3 digits
+        max_value = (10 ** num_digits) - 1   # e.g., 999 for 3 digits
+        
+        expression, result = self._generate_task(item_rng, num_terms, min_value, max_value)
             
         return {
             "question": f"{expression} =",
@@ -68,21 +72,18 @@ class ChainSum:
             }
         }
 
-    def _generate_task(self, rng: random.Random, num_terms: int, num_digits: int) -> tuple[str, int]:
+    def _generate_task(self, rng: random.Random, num_terms: int, min_value: int, max_value: int) -> tuple[str, int]:
         """Generate a chain sum task
         
         Args:
             rng: Random number generator
             num_terms: Number of terms in the expression
-            num_digits: Number of digits for each number
+            min_value: Minimum value for generated numbers
+            max_value: Maximum value for generated numbers
             
         Returns:
             Tuple of (expression string, result integer)
         """
-        # Generate numbers with at least min_digits
-        min_value = 10 ** (num_digits - 1)  # e.g., 100 for 3 digits
-        max_value = (10 ** num_digits) - 1   # e.g., 999 for 3 digits
-        
         if self.config.allow_negation:
             # Allow both positive and negative numbers in the range
             constants = [rng.randint(-max_value, max_value) for _ in range(num_terms)]