A's number is 240, which is 20 less than 80% of B's number. Find B's number.
甲数是240，比乙数的80%少20，求乙数．
<gadget id="calculator">240 + 20</gadget>
<output>260</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">260 / (4/5)</gadget>
<output>325</output>

<result>325</result>