Pour 84L of water into a fish tank with a length of 7dm, a width of 4dm, and a height of 5dm. How many decimeters is the water surface from the side of the tank?
把84L水倒入一个长7dm、宽4dm、高5dm的鱼缸内，水面距缸边有多少分米？
<gadget id="calculator">7 * 4</gadget>
<output>28</output>

<gadget id="calculator">84 / 28</gadget>
<output>3</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<result>2</result>