A store ships 4 boxes of shoes, each box contains 20 pairs. Each pair sells for 8 yuan, how much can you sell in total? (answer in two ways)
一个商店运进4箱鞋，每箱是20双．每双卖8元，一共可以卖多少元？(用两种方法解答)
<gadget id="calculator">8 * 20</gadget>
<output>160</output>

<gadget id="calculator">4 * 160</gadget>
<output>640</output>

<result>640</result>