Xiaomei has 8 red balloons and 63 yellow balloons. To make the number of yellow balloons 9 times that of red balloons, how many yellow balloons need to be added?
小梅有8个红气球，63个黄气球，要使黄气球是红气球的9倍，需要增加多少个黄气球．
<gadget id="calculator">8 * 9</gadget>
<output>72</output>

<gadget id="calculator">72 - 63</gadget>
<output>9</output>

<result>9</result>