Uncle Zhang rented a fruit warehouse at a monthly rent of 1,000 yuan and stored 5 tons of fruit. According to the usual practice, these fruits need to be sold for 4 months. As a result of lowering the selling price, it was sold out in 2 months. Due to the savings in rent, after the settlement, I earned an extra 800 yuan. How much is it lower than planned per kilogram of fruit in sales?
张叔叔以每月1000元的租金租用了一个果品仓库，存进去5吨水果．按照惯例这些水果需要销售4个月．由于降低了销售价格，结果2个月就销售完了．由于节省了租金，结算下来，反而多赚了800元．销售时每千克水果比计划降低了多少元？
<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">1_000 * 2</gadget>
<output>2_000</output>

<gadget id="calculator">2_000 - 800</gadget>
<output>1_200</output>

<gadget id="calculator">5 * 1_000</gadget>
<output>5_000</output>

<gadget id="calculator">1_200 / 5_000</gadget>
<output>6/25 = around 0.24</output>

<result>6/25 = around 0.24</result>