Grandma said to Xiaoming on her birthday: "I have only had 18 birthdays since I was born." How old should grandma be this year?
奶奶生日那天对小明说："我出生以后只过了18个生日．"奶奶今年应该是多少岁．
<gadget id="calculator">18 * 4</gadget>
<output>72</output>

<result>72</result>