18/486 = 0.037 recurring (that is, 0.037037037...)
0.0432
486 divided by 7 with a remainder = 69.42857142857143
0.0556
To divide by a fraction, multiply by its reciprocal. In this instance, 486 / 2/3 = 486 x 3/2 = 729.
13.8857
It is, but not neatly, and it doesn't result in an integer. If you divide 18 by 486, you get .037037...
486
37.3846
54
0.0432
97.2
The greatest common factor of 2250 , 486 = 18
69.4286
486 divided by 7 with a remainder = 69.42857142857143
The GCF is 18.
0.0556
0.0021