Wang Fang bought a box of toothpaste with a net content of 72 cubic centimeters. The diameter of the circular outlet of the toothpaste is 8 mm. She brushes her teeth in the morning and evening. ? (Pi takes an integer value of 3)
王芳买了一盒净含量为72立方厘米的牙膏，牙膏圆形出口直径为8毫米，她早晚各刷牙一次，每次挤出牙膏长约15毫米，这盒牙膏大约能供她使用多少天？(圆周率π取整数值3)
<gadget id="calculator">0.8 / 2</gadget>
<output>0.4</output>

<gadget id="calculator">0.4 ** 2</gadget>
<output>0.16</output>

<gadget id="calculator">3 * 0.16 * 1.5 * 2</gadget>
<output>1.44</output>

<gadget id="calculator">72 / 1.44</gadget>
<output>50</output>

<result>50</result>