Dad plans to pave the upper bricks for the bright little study room. It takes 100 square bricks with a side length of 3 decimeters. If the square bricks with a side length of 5 decimeters are used instead, how many square bricks are needed? (Solve with ratio)
爸爸打算给亮亮的小书房铺上方砖，用边长3分米的方砖需要100块，如果改用边长5分米的方砖，需要方砖多少块？(用比例解)
<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">9 * 100</gadget>
<output>900</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">900 / 25</gadget>
<output>36</output>

<result>36</result>