Uncle Liu brought 800 yuan to buy fertilizer. I bought 20 bags of chemical fertilizers, leaving 40 yuan. How much is each bag of fertilizer?
刘叔叔带了800元钱去买化肥．买了20袋化肥，剩下40元．每袋化肥多少元？
<gadget id="calculator">800 - 40</gadget>
<output>760</output>

<gadget id="calculator">760 / 20</gadget>
<output>38</output>

<result>38</result>