Expanded form is when you take a number, and add its digits together, reforming the number. For example, 1,523 would be 1,000 + 500 + 20 + 3 Here are a few examples: 2,000 + 400 + 50 + 7 = 2,457 200,000 + 700 + 10 + 2 = 200,712 50,000 + 800 + 50 + 6 = 50,856 60,000,000 + 200,000 + 50,000 + 1,000 + 400 + 20 + 3 = 60,251,423
So, 20,484,163 is equal to 20,000,000 + 400,000 + 80,000 + 4,000 + 100 + 60 + 3 = 20,484,163
There is a difference because in the spring, there may be more days of rain, therefore that would increase the mean for the spring compared to the other days.