Problem with Excel even in the latest version

I was recently caught out with an Excel feature. Has anyone else noticed the same error in the program? I was creating a column filled with numbers. To do this I entered 1 in the top cell and 1.025 in the cell below. I then highlighted the cells and then stretched them down to fill the cells underneath to get 1, 1.025, 1.05, 1.075 ......This was fine but then in about row 85 something changed. The numbers went up by more than 0.025. it was a small difference that you would probably not notice in a general calculation but I was using the column with the "lookup" formula and as it was no longer exact it was making an error in the returned answer. You need to go to about 10 decimal places to see the aberration. Is there a way of pointing this out to Microsoft? I tried the help lines but they only deal with advice and were not even interested in trying this out for themselves.

You will always have similar problems with computer software.

The number is displayed as a decimal but is stored as a series of ones and zeros.

even when you typed in 1 and 1.025 and filled down

Look at row 58,

when you format the cell to display more decimal places
the number is 2.42499999999999
not 2.425

if you want precise decimals then use a formula,

Thanks for the quick reply. It also fails if you just keep adding 0.025 to the number above. Unfortunately it displays the rounded number to lull you into a false sense of security. I did correct the error once I found it by multiplying the number by 1000, rounding to zero decimal places, calling it an integer using the "Int" formula and then dividing by 1000. I am somewhat surprised that the binary system cannot represent accurately all numbers.