> So, ATMs did impact bank teller jobs by a significant amount. A third of them were made redundant.

That's not quite my read - the original says per branch there was a 1/3 reduction, but your comment appears to say 1/3 total redundancy.

There was, according to the original, a 40% increase in number of branches, meaning a net increase in tellers (my math might be off though)

edit:

100 branches → 140 branches = +40%

100 tellers/branch → 67 tellers/branch = -33%

140 × 67 = 9,380

100 × 100 = 10,000

net difference -620 or just over 6% (loss)