A cow weighs 500 kg. According to this calculation, how many tons does the two cows weigh?
一头牛重500千克，照这样计算，两头牛重多少吨．
<gadget id="calculator">500 * 2</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 / 1_000</gadget>
<output>1</output>

<result>1</result>