Xiaogang aligned his watch at 9:00 p.m., but when he arrived at school at 8:00 the next morning, he was 10 minutes late when he thought he would arrive at school on time. So Xiaogang's watch was slow by how many minutes per hour?
小刚晚上9时将手表对准，可第二天早上8点到校时，他以为能准时到校，却迟到了10分钟，那么小刚的手表每小时慢几分钟？
<gadget id="calculator">660 * 60</gadget>
<output>39_600</output>

<gadget id="calculator">660 + 10</gadget>
<output>670</output>

<gadget id="calculator">39_600 / 670</gadget>
<output>3_960/67 = around 59.104478</output>

<gadget id="calculator">60 - (3_960/67)</gadget>
<output>60/67 = around 0.895522</output>

<result>60/67 = around 0.895522</result>