I'm 59, grew up near Manchester airport.

Chant was 'in out in on, in out together in'

in - feet inside the elastic bands
out - feet outside
on - jump to place feet on top of elastic bands
Together - bring feet together (with a small jump) with the elastic between them.

We started with the elastics around two people's ankles, and increased the height after each sequence. I'm guessing I was about 8 years old. I only remember the girls playing, but we had segregated playgrounds, so I might not have noticed if the boys did it.

teh 'elastics' were always joined up elastic bands.