Ding Ding is 15 years old this year, and Ding Ding's mother is 43 years old this year. Ask how many years ago Ding Ding's mother was 5 times the age of Ding Ding.
丁丁今年15岁，丁丁的妈妈今年43岁，问多少年前丁丁妈妈的年龄是丁丁的5倍．
<gadget id="calculator">15 * 5</gadget>
<output>75</output>

<gadget id="calculator">75 - 43</gadget>
<output>32</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

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

<result>8</result>