I think the instructions here call for a backward loop cast on but for some reason I can't knit that! I recently tried the heart hot pad and I just used the long tail method and cast on twice the number of squares on the chart plus 2.
I guess that's the way it is with the backwards loop cast-on. Probably when the loop is knitted, the loop after thet is pulled tighter, so the strand between the needles is made longer. That's the way it is, I think