A bottle of purified water has 500 ml, and a supermarket sells 80 bottles in 3 hours. How many liters of this water are there?
一瓶纯净水有500毫升，一家超市3小时卖出80瓶，这些水有多少升？
<gadget id="calculator">500 * 80</gadget>
<output>40_000</output>

<gadget id="calculator">40_000 / 1_000</gadget>
<output>40</output>

<result>40</result>