add a helper function to handle redundant code

reasoning_gym/arithmetic/products.py

@@ -2,6 +2,8 @@ import random
 from dataclasses import dataclass
 from typing import Dict, Optional
 
+from reasoning_gym import utils
+
 from ..coaching import AttributeType, BaseCurriculum, RangeAttributeDefinition
 from ..factory import ProceduralDataset, register_dataset
 
@@ -101,19 +103,8 @@ class ProductsDataset(ProceduralDataset):
         return expression, result
 
     def score_answer(self, answer: Optional[str], entry: Dict[str, any]) -> float:
-        """Overwrite this method in derived classes if a single oracle answer is not available."""
         oracle_answer = entry["answer"].strip()
-        reward = 0.0
-        if answer is not None and len(answer) > 0:
-            answer = answer.strip().replace(",", "")
-            if answer == oracle_answer:
-                reward = 1.0
-            elif oracle_answer in answer:
-                reward = len(oracle_answer) / len(answer)
-            else:
-                reward = 0.01
-
-        return reward
+        return utils.compute_reward(answer, oracle_answer)
 
 
 class ProductsCurriculum(BaseCurriculum):