There are 27 1-yuan and 5-yuan renminbi, the total is 47 yuan, how many 1-yuan renminbi are there?
有27张1元和5元的人民币，一共是47元，1元的人民币有多少张．
<gadget id="calculator">27 * 1</gadget>
<output>27</output>

<gadget id="calculator">47 - 27</gadget>
<output>20</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">27 - 5</gadget>
<output>22</output>

<result>22</result>