Uncle Zhang went to the stationery store and bought 3 pens, each of which cost 18 yuan. He gave the salesperson 100 yuan. How much should he get back?
张叔叔到文具用品店买了3支钢笔，每支钢笔18元，他给营业员100元，应找回多少元？
<gadget id="calculator">3 * 18</gadget>
<output>54</output>

<gadget id="calculator">100 - 54</gadget>
<output>46</output>

<result>46</result>