A house is paved with square bricks with an area of 9 square decimeters, and 400 square bricks are exactly covered. How many square bricks are needed if the square bricks with a side length of 60 cm are used instead?
用面积9平方分米的方砖铺一间房子，400块正好铺满．如果改用边长60厘米的方砖需多少块．
<gadget id="calculator">9 * 400</gadget>
<output>3_600</output>

<gadget id="calculator">60 / 10</gadget>
<output>6</output>

<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<gadget id="calculator">3_600 / 36</gadget>
<output>100</output>

<result>100</result>