27 divided by 567 is 0.047619047619
189
-27
0.0141
11.1176
6.9146
0.0378
0.0035
9
6096.6296
0.0159
((567 divided by 3) x 9) divided by 2 = 850.5
A mathemtical trick is to note that all three numbers are divisible by '9'. How do we known this?? Because the sum of the digits in each number adds to '9'. Hence 189, 567, 2187) 189 ; 1 + 8 + 9 = 18 = 1 + 8 = 9 567 ; 5 + 6 + 7 = 18 = 1 + 8 = 9 2187 [ 2 + 1 + 8 + 7 = 18 = 1 + 8 = 9 189/9 = 21 567/ 9 = 63 2187/9 = 243 All three sub-answer will divide by '3' Hence 7,9,81 ( There are NO common factors ) Hence 9 x 3 = 27 is the GCF. NB THis mathemtical 'trick' can only be done with '9'. !!!!!