Xiao Li asked a grandfather who was doing Taijiquan how old he was. The grandfather stopped and said with a smile: "add 16 to my age, divide it by 4, subtract 15 and multiply it by 10, it is exactly 100 years old. Do you know how old I am?" After thinking for a while, Xiaoli told the old man how old I am this year.
小莉问一正打太极拳的老爷爷多大岁数了，老爷爷停下来笑呵呵地说："把我的年龄加上16，除以4，减去15后用10乘，恰好是100岁，你知道我多大年纪了吗？"小莉稍想片刻后告诉了老爷爷今年多少岁．
<gadget id="calculator">100 / 10</gadget>
<output>10</output>

<gadget id="calculator">10 + 15</gadget>
<output>25</output>

<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">100 - 16</gadget>
<output>84</output>

<result>84</result>