To understand the percentage difference between two numbers, we first need to find the absolute difference between them. In this case, the absolute difference between 36 and 45 is 9.

Next, we need to find the average of the two numbers. The average of 36 and 45 is (36+45)/2 = 40.5.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 36 and 45 is (9/40.5) x 100 = 22.22%.

This means that 45 is 22.22% greater than 36. Alternatively, we can say that 36 is 22.22% less than 45.