There are about 700 species of freshwater fish in my country, 65% less than marine fish. How many species of marine fish are there in my country?
我国的淡水鱼类大约有700种，比海洋鱼类少65%．我国的海洋鱼类大约有多少种？
<gadget id="calculator">65 / 100</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">1 - (13/20)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">700 / (7/20)</gadget>
<output>2_000</output>

<result>2_000</result>