diff --git a/solutions/fuel.py b/solutions/fuel.py
index 7b6c29274..8c6e2bb44 100644
--- a/solutions/fuel.py
+++ b/solutions/fuel.py
@@ -16,16 +16,14 @@ def main():
     """
     Continuously prompts the user for a fraction input, converts it
     to a percentage, and displays the result.
-
     """
     while True:
         try:
-            pcent = input("Fraction: ")
-            print(gauge(convert(pcent)))
+            fraction = input("Fraction: ")
+            print(gauge(convert(fraction)))
             break
-        except AssertionError:
-            # Ignore invalid inputs and re-prompt the user
-            pass
+        except AssertionError as e:
+            print(e)  # Display assertion error message and re-prompt the user
 
 
 def convert(fraction):
@@ -39,14 +37,16 @@ def convert(fraction):
         int: The percentage equivalent of the fraction, rounded to the nearest integer.
 
     Raises:
-        AssertionError: If the numerator is greater than the denominator, or if the input is invalid.
-
-    >>> convert("1/2")
-    50
-    >>> convert("3/4")
-    75
-    >>> convert("2/5")
-    20
+        AssertionError: If the numerator is greater than the denominator,
+        or if the input is invalid.
+
+    Examples:
+        >>> convert("1/2")
+        50
+        >>> convert("3/4")
+        75
+        >>> convert("2/5")
+        40
     """
     x, y = fraction.split("/")
 
@@ -57,16 +57,14 @@ def convert(fraction):
 
     x, y = int(x), int(y)
 
-    # Assert that denominator is not zero
     assert y != 0, "Denominator cannot be zero."
-    assert y > 0, "No negative values allowed"
 
-    # Assert that numerator is not greater than denominator
+    assert x >= 0 and y > 0, "Numerator and denominator must be non-negative."
+
     assert x <= y, "Numerator cannot be greater than denominator."
-    assert x >= 0, "No negative values allowed"
 
     # Calculate percentage and round to nearest integer
-    return int(round((x / y) * 100, 0))
+    return round((x / y) * 100)
 
 
 def gauge(percentage):
@@ -78,17 +76,19 @@ def gauge(percentage):
 
     Returns:
         str: 'F' if the percentage is greater than 99, 'E' if less than 1,
-        otherwise the percentage followed by '%'.
-
-    >>> gauge(50)
-    50%
-    >>> gauge(99.5)
-    F
-    >>> gauge(0)
-    E
+             otherwise the percentage followed by '%'.
 
+    Raises:
+        AssertionError: If the percentage is not within the range 0-100.
+
+    Examples:
+        >>> gauge(50)
+        '50%'
+        >>> gauge(100)
+        'F'
+        >>> gauge(0)
+        'E'
     """
-
     # Assert that percentage is within valid range
     assert 0 <= percentage <= 100, "Percentage must be between 0 and 100."