'of' in mathematics means multiplication.
40% of 180 means 40/100 * 180
40/100 * 180
= 0.40 * 180
= 72
1/4 of 320 means 1/4 * 320
1/4 * 320
= 320/4
= 80
40% of 180 is 72
1/4 of 320 is 80
1/4 of 320 is bigger than 40% of 180
You could also say that as:
1/4 of 320 is greater than 40% of 180.
