Step 1: Start with the fraction 6/21.

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

6 ÷ 21 = 0.2857

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

0.2857 × 100 = 28.57%

Final Answer: 6/21 as a percentage is 28.57%.