Xia Hua is 7 years old this year. He is 28 years younger than his father. How much younger was he than his father last year?
夏华今年7岁，他比爸爸小28岁，去年他比爸爸小多少岁？
<gadget id="calculator">28 + 7</gadget>
<output>35</output>

<gadget id="calculator">35 - 1</gadget>
<output>34</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">34 - 6</gadget>
<output>28</output>

<result>28</result>