Lijiazhuang plans to dig a 900-meter ditch, digging 150 meters a day for 5 days, how many meters are left to be dug?
李家庄计划挖一条900米的水沟，每天挖150米，挖了5天，还剩多少米没挖？
<gadget id="calculator">150 * 5</gadget>
<output>750</output>

<gadget id="calculator">900 - 750</gadget>
<output>150</output>

<result>150</result>