As a fraction 9/10
60 over 270 in lowest terms is 2/9
90% of 270= 90% * 270= 0.9 * 270= 243
234/270 = 13/15
113/135
.270
270/210 = 27/21 = 4/3 = 1 1/3 or 1.333
.270 is the larger calibre of the two.
The LCM is: 243
The parent case of the .270 is the .30-06, necked down. The parent case of the .243 is the .308 Winchester, necked down. Aside from the larger diameter of the .270, the .270 has a longer case.
10 percent off is 90% of 270 dollars 270 x 0.9 = 243 270 - 10% is $243.00
If 7mm Magnum, it trumps the others.
Really depends on the load, but the .270 is typically the more powerful of the two.