Xiao Ming is 15 years old this year, and his grandfather is 4 times as old as Xiao Ming, which is more than 4 years old. How old is grandpa this year?
小明今年15岁，爷爷的年龄是小明年龄的4倍还多4岁，爷爷今年多少岁了？
<gadget id="calculator">15 * 4</gadget>
<output>60</output>

<gadget id="calculator">60 + 4</gadget>
<output>64</output>

<result>64</result>