Arrange the five numbers 1, 2, 3, 4, and 5 in a line from large to small, and insert a plus sign arbitrarily between these five numbers, how many different sums can be obtained.
将1，2，3，4，5这五个数字从大到小排成一行，在这五个数中间任意插入加号，可以得到多少个不同的和．
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">4 * (3/2)</gadget>
<output>6</output>

<gadget id="calculator">1 + 4 + 6 + 4</gadget>
<output>15</output>

<result>15</result>