The school uses square floor tiles with a side length of 8 decimeters to pave the multi-functional classroom, and it needs 240 pieces. If it uses rectangular floor tiles with a length of 5 decimeters and a width of 4 decimeters, how many pieces are needed?
学校用边长8分米的正方形地砖给多功能教室铺地面，需要240块，如果改用长5分米，宽4分米的长方形地砖，需要多少块？
<gadget id="calculator">8 * 8 * 240</gadget>
<output>15_360</output>

<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">15_360 / 20</gadget>
<output>768</output>

<result>768</result>