Choose a number from 1, 2, and 3 as the numerator, and choose a number from 5, 6, and 7 as the denominator. How many fractions can be formed in total?
从1、2、3中任选一个数作为分子，从5，6，7中任选一个数作为分母，一共可以组成多少个分数．
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<result>9</result>