A stone pillar weighs 500 kg, how many tons does four such stone pillars weigh?
一根石柱重500千克，4根这样的石柱重多少吨．
<gadget id="calculator">4 / 1_000</gadget>
<output>1/250 = around 0.004</output>

<gadget id="calculator">500 * (1/250)</gadget>
<output>2</output>

<result>2</result>