Dad's age is 27 years older than Mingming's. Next year's father's age will be four times that of Mingming's. Do you know how old Mingming is this year?
爸爸的年龄比明明大27岁，明年爸爸的年龄是明明的4倍，你知道今年明明是多少岁吗？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">27 / 3</gadget>
<output>9</output>

<gadget id="calculator">9 - 1</gadget>
<output>8</output>

<result>8</result>