There is a batch of books that are distributed to grades 4, 5, and 6 according to the ratio of 1:2:3, and 180 books are distributed to grade 6. How many books are there in this batch?
有一批图书，按1：2：3的比例分给4、5、6三个年级，六年级分得180本，这批图书共有多少本？
<gadget id="calculator">180 / 3</gadget>
<output>60</output>

<gadget id="calculator">1 + 2 + 3</gadget>
<output>6</output>

<gadget id="calculator">60 * 6</gadget>
<output>360</output>

<result>360</result>