The factors of \({6}\) are \({1}\), \({2}\), \({3}\) and \({6}\). The factors of \({10}\) are \({1}\), \({2}\), \({5}\) and \({10}\).

1 is a common factor of all whole numbers. To find common factors: List the factors of each number. Compare the factors to find numbers that are the same (or common) in each list.