There are 84 students in class one, grade one, and boys account for 2/7 of the whole class. How many boys are there?
一年级一班有84人，男生占全班人数的(2/7)，男生有多少人？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">84 * (2/7)</gadget>
<output>24</output>

<result>24</result>