Limin Township wants to dig a 900-meter-long canal. It has been digging for 8 days, and 45 meters are dug every day. How many meters are left to be dug?
利民乡要挖一条长900米的水渠，已经挖了8天，每天挖45米，还有多少米没挖？
<gadget id="calculator">45 * 8</gadget>
<output>360</output>

<gadget id="calculator">900 - 360</gadget>
<output>540</output>

<result>540</result>