diff --git a/reasoning_gym/algorithmic/base_conversion.py b/reasoning_gym/algorithmic/base_conversion.py
index c1f62654..afa6200a 100644
--- a/reasoning_gym/algorithmic/base_conversion.py
+++ b/reasoning_gym/algorithmic/base_conversion.py
@@ -61,9 +61,9 @@ class BaseConversionDataset(ProceduralDataset):
 
         # Convert decimal to source base representation
         if source_base == 16:
-            source_repr = format(value, 'x')
+            source_repr = format(value, "x")
         elif source_base == 2:
-            source_repr = format(value, 'b')
+            source_repr = format(value, "b")
         else:
             # Manual conversion for other bases
             n = value
@@ -71,14 +71,13 @@ class BaseConversionDataset(ProceduralDataset):
             while n:
                 digits.append(int(n % source_base))
                 n //= source_base
-            source_repr = ''.join(str(d) if d < 10 else chr(ord('a') + d - 10) 
-                                for d in reversed(digits) or [0])
+            source_repr = "".join(str(d) if d < 10 else chr(ord("a") + d - 10) for d in reversed(digits) or [0])
 
         # Convert decimal to target base for answer
         if target_base == 16:
-            target_repr = format(value, 'x')
+            target_repr = format(value, "x")
         elif target_base == 2:
-            target_repr = format(value, 'b')
+            target_repr = format(value, "b")
         else:
             # Manual conversion for other bases
             n = value
@@ -86,8 +85,7 @@ class BaseConversionDataset(ProceduralDataset):
             while n:
                 digits.append(int(n % target_base))
                 n //= target_base
-            target_repr = ''.join(str(d) if d < 10 else chr(ord('a') + d - 10) 
-                                for d in reversed(digits) or [0])
+            target_repr = "".join(str(d) if d < 10 else chr(ord("a") + d - 10) for d in reversed(digits) or [0])
 
         source_name = self._format_base_name(source_base)
         target_name = self._format_base_name(target_base)
diff --git a/tests/test_base_conversion.py b/tests/test_base_conversion.py
index 2f12eaa9..8017d74a 100644
--- a/tests/test_base_conversion.py
+++ b/tests/test_base_conversion.py
@@ -65,12 +65,12 @@ def test_base_conversion_dataset_items():
         # Verify conversion correctness
         decimal_value = item["metadata"]["decimal_value"]
         target_base = item["metadata"]["target_base"]
-            
+
         # Use same conversion logic as implementation
         if target_base == 16:
-            expected = format(decimal_value, 'x')
+            expected = format(decimal_value, "x")
         elif target_base == 2:
-            expected = format(decimal_value, 'b')
+            expected = format(decimal_value, "b")
         else:
             # Manual conversion for other bases
             n = decimal_value
@@ -78,8 +78,7 @@ def test_base_conversion_dataset_items():
             while n:
                 digits.append(int(n % target_base))
                 n //= target_base
-            expected = ''.join(str(d) if d < 10 else chr(ord('a') + d - 10)
-                             for d in reversed(digits) or [0])
+            expected = "".join(str(d) if d < 10 else chr(ord("a") + d - 10) for d in reversed(digits) or [0])
         assert item["answer"] == expected
 
 
@@ -97,14 +96,7 @@ def test_base_conversion_dataset_iteration():
 
 def test_base_conversion_validity():
     """Test that generated numbers are valid for their bases"""
-    config = BaseConversionConfig(
-        min_base=2,
-        max_base=36,
-        min_value=0,
-        max_value=1000,
-        size=100,
-        seed=42
-    )
+    config = BaseConversionConfig(min_base=2, max_base=36, min_value=0, max_value=1000, size=100, seed=42)
     dataset = BaseConversionDataset(config)
 
     def is_valid_for_base(num_str: str, base: int) -> bool:
@@ -113,12 +105,12 @@ def test_base_conversion_validity():
 
     for i in range(len(dataset)):
         item = dataset[i]
-        assert is_valid_for_base(item["metadata"]["source_repr"], 
-                               item["metadata"]["source_base"]), \
-            f"Invalid source number {item['metadata']['source_repr']} for base {item['metadata']['source_base']}"
-        assert is_valid_for_base(item["metadata"]["target_repr"], 
-                               item["metadata"]["target_base"]), \
-            f"Invalid target number {item['metadata']['target_repr']} for base {item['metadata']['target_base']}"
+        assert is_valid_for_base(
+            item["metadata"]["source_repr"], item["metadata"]["source_base"]
+        ), f"Invalid source number {item['metadata']['source_repr']} for base {item['metadata']['source_base']}"
+        assert is_valid_for_base(
+            item["metadata"]["target_repr"], item["metadata"]["target_base"]
+        ), f"Invalid target number {item['metadata']['target_repr']} for base {item['metadata']['target_base']}"
 
 
 def test_base_conversion_special_bases():