A whale is 7 meters long, and the head accounts for 2/5 of the total length. How long is the body of this whale except the head?
一头鲸长7米，头部长占全长的(2/5)，这头鲸除头外的身体有多长？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">7 * (2/5)</gadget>
<output>14/5 = around 2.8</output>

<gadget id="calculator">7 - (14/5)</gadget>
<output>21/5 = around 4.2</output>

<result>21/5 = around 4.2</result>