The father is 27 years older than the son. After 4 years, the father will be 4 times the son's age. How old is the father now?
父亲比儿子的年龄大27岁，4年后父亲的年龄是儿子年龄的4倍，父亲现在多少岁？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

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

<gadget id="calculator">9 - 4</gadget>
<output>5</output>

<gadget id="calculator">27 + 5</gadget>
<output>32</output>

<result>32</result>