The school distributes (3/5) the purchased books to the fourth, fifth and sixth grades according to the ratio of 2:3:4. It is known that the sixth grade is divided into 56 books. How many books did the school buy in total?
学校把购进图书的(3/5)按2：3：4分给四、五、六年级，已知六年级分到56本，学校共购进图书多少本？
<gadget id="calculator">2 + 3 + 4</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">56 / (4/9) / (3/5)</gadget>
<output>210</output>

<result>210</result>