Daniel Tammet said this quote
“ Perhaps talk of counters turned the boy’s thoughts to his father’s glove shop. His father would have accounted for all his transactions using the tokens. They were hard and round and very thin, made of copper or brass. There were counters for one pair of gloves, and for two pairs, and three and four and five. But there was no counter for zero. No counters existed for all the sales that his father did not close. ”