Zhang Jun's family bought a bag of rice and ate an average of 2 kilograms per day. After eating for 9 days, there were still 7 kilograms left. How many kilograms is this bag of rice originally?
张军家买回一袋大米，平均每天吃2千克，吃了9天后还剩下7千克．这袋大米原有多少千克．
<gadget id="calculator">2 * 9</gadget>
<output>18</output>

<gadget id="calculator">18 + 7</gadget>
<output>25</output>

<result>25</result>