Zhang Yang uses 20 chess pieces to form a square, how many pieces are there on each side?
张洋用20个棋子摆成一个正方形，每边上有多少个棋子．
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<result>6</result>