Xiaodong's father looked at the clock when he went out in the morning. It was 6 o'clock. When he came back from his work, he found that the clock had turned 90 degrees. What time was it when Xiaodong's father came back?
小东的爸爸早上出门时看了看钟，6时整，当他办完事回来时发现时钟已转动90度，小东爸爸回来是多少时．
<gadget id="calculator">90 / 30</gadget>
<output>3</output>

<gadget id="calculator">6 + 3</gadget>
<output>9</output>

<result>9</result>