Common factors: 1, 2.
factors of 4 are: 1, 2, 4
factors of 36 (up to 4) are: (1, 2, 3, 4), 6, 9, 12, 18, 36
factors of 58 (up to 4) are: (1, 2), 29, 58
Factors of 1,000 (up to 4) are: (1, 2, 4), 5, 8, 10, etc…
Common factors mean that each number must have that factor, like each number having a common factor of 1. If only two of the listed numbers have a common factor, we won’t include it.
The largest factor of 4 is 4, so we cannot go higher than that for the possible common factors.
4, 36, 58, and 1,000 have common factors of:
1 and 2.