To find the percentage difference between two numbers, we first need to calculate the absolute difference between them. In this case, the absolute difference between 76 and 80 is 4.

Next, we need to find the average of the two numbers. The average of 76 and 80 is (76+80)/2 = 78.

Now, we can calculate the percentage difference by dividing the absolute difference by the average and multiplying by 100. So, the percentage difference between 76 and 80 is (4/78) x 100 = 5.13%.

Therefore, the percentage difference between 76 and 80 is 5.13%. This means that 80 is 5.13% greater than 76.