Minor question template & score_answer improvements (#261)

* math prompt improvements
* ignore brackets in complex_arithmetic results
* improve additional instruction in prompt of polynomial_equations
* more strict tests for score_answer in polynomial_equations
* simplify special reward handling
* fix test_intermediate_integration
* fix sokoban dataset
* add common dataset score_answer consistency test

reasoning_gym/arithmetic/decimal_chain_sum.py

@@ -1,6 +1,6 @@
 import random
 from dataclasses import dataclass
-from decimal import Decimal
+from decimal import Decimal, InvalidOperation
 from typing import Any, Optional
 
 from ..factory import ProceduralDataset, register_dataset
@@ -129,7 +129,11 @@ class DecimalChainSumDataset(ProceduralDataset):
                 result -= c
 
         expression = " ".join(expression_parts)
-        result = result.quantize(Decimal(f"0.{'0' * max(decimal_places)}"))
+        try:
+            q = Decimal(f"0.{'0' * max(decimal_places)}")
+            result = result.quantize(q)
+        except InvalidOperation:
+            pass
         return expression, result
 
     def score_answer(self, answer: Optional[str], entry: dict[str, Any]) -> float:
@@ -141,16 +145,19 @@ class DecimalChainSumDataset(ProceduralDataset):
         Returns:
             1.0 for exact numerical match, 0.01 otherwise
         """
-        if answer is None or len(answer.strip()) == 0:
+        if not isinstance(answer, str) or len(answer.strip()) == 0:
             return 0.0
 
         try:
             student_answer = Decimal(answer.strip())
             oracle_answer = Decimal(entry["answer"])
 
-            return 1.0 if student_answer == oracle_answer else 0.01
-        except (ValueError, TypeError, ArithmeticError):
-            return 0.01
+            if student_answer == oracle_answer:
+                return 1.0
+        except Exception:
+            pass
+
+        return 0.0
 
 
 register_dataset("decimal_chain_sum", DecimalChainSumDataset, DecimalChainSumConfig)