There is a batch of "Love Mathematics since Childhood" in the bookstore. 15% of them were sold on the first day, and 200 copies were sold on the second day. ?
书店有一批《从小爱数学》，第一天卖出15%，第二天卖出200本，两天卖出的与剩下的比是2：3，书店原来有《从小爱数学》多少本？
<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(2/5) - (3/20)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">200 / (1/4)</gadget>
<output>800</output>

<result>800</result>