There are two wheat fields, A and B, with an average yield of 520 kg of wheat per mu. A wheat field has 10 mu, and the average yield per mu is 500 kg of wheat. If the average wheat yield per mu of B wheat field is 560 kg, how many mu does B wheat field have?
有甲、乙两块麦田，平均亩产小麦520千克．甲块麦田有10亩，平均亩产小麦500千克．如果乙块麦田平均亩产小麦560千克，那么乙块麦田有多少亩．
<gadget id="calculator">520 * 10</gadget>
<output>5_200</output>

<gadget id="calculator">500 * 10</gadget>
<output>5_000</output>

<gadget id="calculator">5_200 - 5_000</gadget>
<output>200</output>

<gadget id="calculator">560 - 520</gadget>
<output>40</output>

<gadget id="calculator">200 / 40</gadget>
<output>5</output>

<result>5</result>