I have 24 columns. In columns 25 and 26, I want the sum totals of every other
column to its left. In other words, column 25 would show the sum of columns,
1,3,5,7,... and column 26 the sum of columns 2,4,6,8,....

I have manually entered the formula =sum(a1+c1+e1+.....x1). Is there an
easier way?

Thanks in advance