If a house is paved with square marble, 360 pieces are needed for a side length of 0.4 decimeters. If the square marble is used instead, how many pieces are needed?
一间房子用正方形大理石铺地，用边长0.4分米的需360块，如果改用面积为0.09的大理石，需要多少块？
<gadget id="calculator">360 / 0.09</gadget>
<output>4_000</output>

<gadget id="calculator">0.4 * 0.4 * 4_000</gadget>
<output>640</output>

<result>640</result>