After subtracting 15 from the age of Xiao Ming's grandfather this year, divide it by 4, then subtract 6, and multiply it by 10 times, which is exactly 100 years old. How old is Xiao Ming's grandfather this year?
小明的爷爷今年的年纪减去15后，除以4，再减去6之后，扩大10倍，恰好是100岁，小明的爷爷今年多少岁．
<gadget id="calculator">100 / 10</gadget>
<output>10</output>

<gadget id="calculator">10 + 6</gadget>
<output>16</output>

<gadget id="calculator">16 * 4</gadget>
<output>64</output>

<gadget id="calculator">64 + 15</gadget>
<output>79</output>

<result>79</result>