Grass can renew the air, and 10,000 square meters of green space can release 1.05 tons of oxygen a week. A certain farm has a 40,000 square meter green space. How many tons of oxygen can this green space release in October this year?
草能更新空气，10000平方米的绿地一周能释放出1.05吨的氧气．某农场有一块40000平方米的绿地，今年十月份这块绿地可以释放多少吨氧气？
<gadget id="calculator">40_000 / 10_000</gadget>
<output>4</output>

<gadget id="calculator">1.05 / 7</gadget>
<output>0.15</output>

<gadget id="calculator">4 * 0.15 * 31</gadget>
<output>18.6</output>

<result>18.6</result>