The grain store shipped 50 bags of flour, each bag of flour weighed 25 kilograms, and sold 29 bags, how many kilograms are left?
粮店运来面粉50袋，每袋面粉重25千克，卖出29袋，还剩多少千克？
<gadget id="calculator">50 - 29</gadget>
<output>21</output>

<gadget id="calculator">21 * 25</gadget>
<output>525</output>

<result>525</result>