A box of color film can take up to 36 photos. According to this calculation, how many photos can be taken with 15 boxes of film.
一盒彩色胶卷最多能拍36张照片，照这样计算，15盒胶卷最多可以拍多少张照片．
<gadget id="calculator">36 * 15</gadget>
<output>540</output>

<result>540</result>