Write numbers on six sides of a cube so that after the cube is thrown, the possibility of 5 facing up is 1/2. How many sides of the cube should be written with 5?
在一个正方体的六个面写上数字，使得正方体掷出后，5朝上的可能性为二分之一，正方体有多少个面要写上5．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">6 * (1/2)</gadget>
<output>3</output>

<result>3</result>