Divide 720 books to the sixth grade and fifth grade according to the ratio of 5:4, how many books are allocated to the fifth grade.
把720本图书按照5：4分给六年级和五年级，五年级分得图书多少本．
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

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

<gadget id="calculator">720 * (4/9)</gadget>
<output>320</output>

<result>320</result>