Can you upload excel spreadsheets to icloud without numbers?

I am just starting to use icloud and have tired dragging my excel created spreadsheets to icloud "numbers" but it doesn't work. I keep getting the message "There was a problem uploading a spreadsheet Please try again" so is this because I don't have Apple's "Numbers"? I have also tried uploading Words documents to "Pages" and the same thing happens.

Please help!