The school cafeteria uses 400 pairs of disposable chopsticks every day, and each pair of chopsticks is 0.03 yuan. How much is the chopsticks used in a week?
学校食堂每天要用掉一次性筷子400双，每双筷子0.03元．一周用掉的筷子一共多少钱？
<gadget id="calculator">0.03 * 400 * 7</gadget>
<output>84</output>

<result>84</result>