The area of Lingling's study room is 16m**2, and it is paved with floor tiles with a side length of 2 decimeters. How many pieces are needed in total?
玲玲家书房的面积是16米**2，用边长是2分米的地砖来铺，一共需多少块？
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<gadget id="calculator">16 * 25</gadget>
<output>400</output>

<result>400</result>