Step 1: Start with the fraction 1/21.

Step 2: To convert a fraction into a percentage, divide the numerator by the denominator.

1 ÷ 21 = 0.0476

Step 3: Multiply the result by 100 to get the percentage.

0.0476 × 100 = 4.76%

Final Answer: 1/21 as a percentage is 4.76%.