During the Spring Festival, the eight old friends made a phone call to say hello to each other. How many calls did they make in total?
过春节的时候，8名老朋友间都通了一次电话相互问好．他们一共打了多少个电话．
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">7 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">8 * (7/2)</gadget>
<output>28</output>

<result>28</result>