Xiao Ming is 12 years old this year, and Xiao Jie is 3 years older than him. After three years, what fraction of Xiao Ming's age will be Xiao Jie's age? How many.
小明今年12岁，小杰比他大3岁，三年后，小明年龄是小杰年龄的几分之几？多少．
<gadget id="calculator">12 + 3</gadget>
<output>15</output>

<gadget id="calculator">15 + 3</gadget>
<output>18</output>

<gadget id="calculator">15 / 18</gadget>
<output>5/6 = around 0.833333</output>

<result>5/6 = around 0.833333</result>