A box of color film can take up to 36 photos. According to this calculation, how many photos can be taken with 18 boxes of film.
一盒彩色胶卷最多能拍36张照片，照这样计算，18盒胶卷最多可以拍多少张照片．
<gadget id="calculator">36 * 18</gadget>
<output>648</output>

<result>648</result>