Shangde Primary School bought 20 boxes of green tea, 12 bottles per box, 3 yuan per bottle. How much did Shangde Primary School spend on green tea?
尚德小学买来20箱绿茶，每箱12瓶，每瓶3元．尚德小学买绿茶共花多少钱？
<gadget id="calculator">3 * 12 * 20</gadget>
<output>720</output>

<result>720</result>