Answer:
Leia needs 3 * 417 = <<3*417=1251>>1251 batteries for her cars.
Explanation:
To find out how many batteries Leia needs for her cars, we need to multiply the number of toy cars by the number of batteries needed for each car. Since each car needs 3 batteries and Leia has 417 toy cars, the total number of batteries she needs is 3 * 417 = 1251.