A pile of coal weighs 3 tons. How many kilograms are left after 1200 kilograms are removed?
一堆煤重3吨，运走了1200千克后还剩多少千克．
<gadget id="calculator">3 * 1_000</gadget>
<output>3_000</output>

<gadget id="calculator">3_000 - 1_200</gadget>
<output>1_800</output>

<result>1_800</result>