Oddly, the homesigners did use their fingers to keep track of objects, the way children use their fingers to count. Spaepen thinks the signers use each individual finger to represent a unique object — the index finger is the red fish, the middle finger is the blue fish — and not the abstract concept of the number of fish.
“They can’t represent something like exactly seven,” Spaepen said. “What they have is a representation of one-one-one-one-one-one-one.”