Pour 18 liters of water into a cuboid glass tank with a length of 4 decimeters, a width of 3 decimeters, and a height of 2 decimeters. How many decimeters is the water surface from the mouth of the tank?
把18升水倒人一个长4分米、宽3分米、高2分米的长方体玻璃缸内，水面距缸口多少分米？
<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<gadget id="calculator">18 / 12</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">2 - (3/2)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>