Divide 280 books between class 1 and class 2 according to the ratio of 5:3.
把280本书按5：3分给一班和二班，一班比二班多分多少本．
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">280 / 8</gadget>
<output>35</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">35 * 2</gadget>
<output>70</output>

<result>70</result>