For Xiaohong's birthday, her mother bought a birthday cake. Xiaohong ate this cake (8/15), and ate more cake than her father (1/4). Dad and Xiaohong ate a fraction of the cake together. Several?
小红过生日，妈妈买了一个生日蛋糕，小红吃了这个蛋糕的(8/15)，比爸爸多吃了蛋糕的(1/4)，爸爸和小红一共吃了蛋糕的几分之几？
<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(8/15) - (1/4)</gadget>
<output>17/60 = around 0.283333</output>

<gadget id="calculator">(17/60) + (8/15)</gadget>
<output>49/60 = around 0.816667</output>

<result>49/60 = around 0.816667</result>