9 kilometers per hour = how many meters per second.
9千米/时=多少米/秒．
<gadget id="calculator">9 * 1_000</gadget>
<output>9_000</output>

<gadget id="calculator">9_000 / 3_600</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>