12+15+18+...+96．
12+15+18+…+96．
<gadget id="calculator">12 + 96</gadget>
<output>108</output>

<gadget id="calculator">96 - 12</gadget>
<output>84</output>

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

<gadget id="calculator">28 + 1</gadget>
<output>29</output>

<gadget id="calculator">29 / 2</gadget>
<output>29/2 = around 14.5</output>

<gadget id="calculator">108 * (29/2)</gadget>
<output>1_566</output>

<result>1_566</result>