81
27,3
9,3,3
3,3,3,3
Ah, finding the greatest common factor is like finding a happy little tree in a forest. For 36 and 81, we look for the largest number that can divide evenly into both. The greatest common factor for 36 and 81 is 9, like a gentle breeze on a sunny day.
9x9=81. Proving that one of the factor trees for 81 is 9xp.
81 27,3 9,3,3 3,3,3,3
81 27,3 9,3,3 3,3,3,3
81 27,3 9,3,3 3,3,3,3
81 27,3 9,3,3 3,3,3,3
3,3,3,39,3,327,381
The factors of 81 are: 1, 3, 9, 27, 81.
81 27,3 9,3,3 3,3,3,3
648 162 4 81 2 2 2 9 9 Equals: 9 squared time 2 cubed.
45 15,3 5,3,3 81 27,3 9,3,3 3,3,3,3
51 3,17 81 9,9 3,3,9 3,3,3,3 The GCF is 3.