arrayformula sum in Google spreadsheet

Question

How do you arrayformula() a sum() such as:

=sum(A1:H1)

I need to go down 1000 rows.

Answer 1

This is what you are looking for:

=MMULT(A1:H1000,TRANSPOSE(ARRAYFORMULA(COLUMN(A1:H1000)^0)))

See this answer on Web Application I gave: https://webapps.stackexchange.com/a/53419/29140

Note: tried it on the new Google Spreadsheet, without succes.