2% of 21

To calculate 2% of 21, you can use the formula:

\[ \text{Percentage} = \left(\frac{\text{Percent}}{100}\right) \times \text{Number} \]

So, for 2% of 21:

\[ 2% \text{ of } 21 = \left(\frac{2}{100}\right) \times 21 = 0.02 \times 21 = 0.42 \]

Therefore, 2% of 21 is 0.42.