There are about 840 species of freshwater fish in my country, 75% less than marine fish. How many species of marine fish are there in my country?
我国淡水鱼类大约有840种，比海洋鱼类少75%．我国的海洋鱼类大约有多少种？
<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">840 / (1/4)</gadget>
<output>3_360</output>

<result>3_360</result>