An old man said, add 25 to his age, divide by 3, subtract 12 and multiply by 4, it is exactly 120 years old, how old is this old man?
一位老爷爷说，他的年龄加上25除以3再减去12后用4乘，正好是120岁，这位老爷爷有多少岁．
<gadget id="calculator">120 / 4</gadget>
<output>30</output>

<gadget id="calculator">30 + 12</gadget>
<output>42</output>

<gadget id="calculator">42 * 3</gadget>
<output>126</output>

<gadget id="calculator">126 - 25</gadget>
<output>101</output>

<result>101</result>