Grandpa is 70 years old this year, 7 years older than 9 times the age of his grandson. How old is your grandson? (solution by equation)
爷爷今年70岁，比小孙子年龄的9倍多7岁．小孙子今年几岁？(用方程解)
<gadget id="calculator">70 - 7</gadget>
<output>63</output>

<gadget id="calculator">63 / 9</gadget>
<output>7</output>

<result>7</result>