The sign HOW-MANY is not the same as the sign for "many."
When signing MANY you start
with the hands higher and a bit closer to my body. Then you move them
outward an inch or two (instead of upward) while changing into the loose "five" handshapes.
Don't use the furrowed eyebrows for "many" (unless you want to
emphasize that there were very many of something) instead
just use a slight nod of the head.