In a Excel spreadsheet, generate in column A starting at A3, integers from 0 to 1023.
In the cells C1 through F1, add numerical columns headers for base 10 numbers. So F1 has 1, E1 has 10, D1 has 100, and C1 has 1000.
Create appropriate formulas and auto fill down to calculate in the digits of the base 10 representation of the numbers is column A.
If you have practiced with Auto Fill and absolute and relative cell reference, you can save some time and pain by creating one formula in cell F3. This formula should refer to the numerical column headers. Then auto fill from F3, to the left over to C3, to generate the other 3 automatically. Then auto fill all 4 columns down to generate the digits of all the numbers.
At the bottom of these column of digits, calculate the average of the digits in each column. Use a cell format with 6 digits after the decimal point for the column averages.
Now do the same thing, except in base 2, over to the right in the 11 columns H through R.
If you saved time by doing the painless formula using the numerical column headers in cell F3 for decimal digits, it should be possible to easily relocate that formula, essentially unchanged except for column letters, over to R3 to do the formulas for the binary digits for free.