To find the percentage difference between two numbers, we first need to find the absolute difference between them. In this case, the absolute difference between 180 and 98 is 82 (|180-98| = 82).

Next, we need to find the average of the two numbers. The average of 180 and 98 is (180+98)/2 = 139.

Now, we can find the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 180 and 98 is (82/139) x 100 = 59.0%.

Therefore, the percentage difference between 180 and 98 is 59.0%. This means that 98 is 59.0% less than 180.