Wang Gang spent 2,400 yuan on a video recorder, which was known to be sold at a 20% discount. How much did Wang Gang spend less?
王刚买一台录像机花了2400元，已知这台录像机是打八折出售的．王刚少花了多少元？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">2_400 / (4/5)</gadget>
<output>3_000</output>

<gadget id="calculator">3_000 - 2_400</gadget>
<output>600</output>

<result>600</result>