There is a lawn of 900 square meters in Hailing Park. This lawn can release 15 grams of oxygen and absorb 20 grams of carbon dioxide per square meter per day. How much more carbon dioxide can this lawn absorb than oxygen released every day?
海陵公园有一块900平方米的草坪，这种草坪每平方米每天能释放氧气15克，吸收二氧化碳20克，这块草坪每天吸收的二氧化碳比放出的氧气多多少克？
<gadget id="calculator">20 - 15</gadget>
<output>5</output>

<gadget id="calculator">5 * 900</gadget>
<output>4_500</output>

<result>4_500</result>