Uncle Li brought 820 yuan to buy fertilizer. I bought 12 bags of chemical fertilizer and left 4 yuan. How much is each bag of chemical fertilizer?
李叔叔带820元买化肥．买了12袋化肥，剩4元，每袋化肥多少元？
<gadget id="calculator">820 - 4</gadget>
<output>816</output>

<gadget id="calculator">816 / 12</gadget>
<output>68</output>

<result>68</result>