There are 21 girls in Class 51, 3 fewer than boys. What percentage of the whole class are boys?
五1班有女生21人，比男生少3人，男生占全班人数的几分之几？
<gadget id="calculator">21 + 3</gadget>
<output>24</output>

<gadget id="calculator">21 + 3 + 21</gadget>
<output>45</output>

<gadget id="calculator">24 / 45</gadget>
<output>8/15 = around 0.533333</output>

<result>8/15 = around 0.533333</result>