Assertion: new abacus | /r/HasProperty | designed with 4 decks
Facets:
Source sentences:
text: In 1958 Lee Kai-chen published a manual for his "new" abacus designed with 4 decks (it combines two abaci; the top abacus is a small 1/4 soroban and the bottom one is a 2/5 suan-pan).
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).