The school distributes 700 books to Grades 1, 2, and 3 according to the ratio of 1:2:4. How much more books are assigned to Grade 3 than Grade 2?
学校把700本书按1：2：4分给一、二、三年级，三年级比二年级多分多少本？
<gadget id="calculator">1 + 2 + 4</gadget>
<output>7</output>

<gadget id="calculator">700 / 7</gadget>
<output>100</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">100 * 2</gadget>
<output>200</output>

<result>200</result>