Dad put a rockery rock in a cuboid fish tank with a bottom area of 51dm**2, and the water surface rose by 3cm. How big is this rockery?
爸爸在一个底面积为51dm**2的长方体鱼缸里放了一个假山石，水面上升了3cm．这个假山石的体积有多大？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">51 * (3/10)</gadget>
<output>153/10 = around 15.3</output>

<result>153/10 = around 15.3</result>