Assertion: abacus | /r/HasProperty | small ¼ soroban
Facets:
Source sentences:
text: The Abacus Today: The image above is a cover of a manual published in 1958 by Lee Kai-chen, the inventor of this “new” abacus designed with 4 decks (essentially, it consists of 2 stacked abaci; the top abacus is a small ¼ soroban and the bottom one is a 2/5 suan-pan).