A blue ball is 78 yuan, Mr. Li bought 12, and gave the salesperson 1,000 yuan, how much did you get back?
一个蓝球78元，李老师买了12个，给营业员1000元，找回多少？
<gadget id="calculator">78 * 12</gadget>
<output>936</output>

<gadget id="calculator">1_000 - 936</gadget>
<output>64</output>

<result>64</result>