Subtract 7 from dad's age, multiply by 3, add 1 to get 100, how old is dad this year?
爸爸的年龄减去7，乘以3，加上1是100，爸爸今年多少岁？
<gadget id="calculator">100 - 1</gadget>
<output>99</output>

<gadget id="calculator">99 / 3</gadget>
<output>33</output>

<gadget id="calculator">33 + 7</gadget>
<output>40</output>

<result>40</result>