Xiao Ming is 5 years old this year. Three years later, his mother will be four times his age. How old is his mother?
小明今年5岁，3年后，妈妈的年龄是他的4倍，妈妈今年多少岁？
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">32 - 3</gadget>
<output>29</output>

<result>29</result>