Answer:
1, 2, 3, 6, 13, 26, 39, 78
Explanation:
The factors of a number are the numbers that "go into" 78 "evenly" that is, without a remainder. You can make a factor tree or divide to find the prime factors. Any combination "goes into" 78. That's why we'll include 6 and 26 on this list.
1×78
2×39
3×26
6×13
all make 78!