Each volleyball in Huaguan Supermarket sells for 67 yuan, and the school needs to buy 2 such volleyballs and pay 150 yuan. How much should I get back?
华冠超市里每个排球卖67元，学校要买2个这样的排球，付150元．应找回多少元？
<gadget id="calculator">67 * 2</gadget>
<output>134</output>

<gadget id="calculator">150 - 134</gadget>
<output>16</output>

<result>16</result>