The school bought 850 prizes on Children's Day, and after distributing these prizes to 15 activities on average, there are 10 left. How many prizes are there on average for each activity?
儿童节学校买来850件奖品，这些奖品平均分给15个活动项目后，还剩10件，平均每个活动项目有多少件奖品？
<gadget id="calculator">850 - 10</gadget>
<output>840</output>

<gadget id="calculator">840 / 15</gadget>
<output>56</output>

<result>56</result>