The department store sells 3 boxes of trousers, 20 pairs in each box, and 21 yuan each. How much is it sold in total?
百货商店卖出3箱西裤，每箱20条，每条21元，一共卖了多少元？
<gadget id="calculator">21 * 20 * 3</gadget>
<output>1_260</output>

<result>1_260</result>