Assertion: abacus | /r/HasProperty | small 1/4 soroban
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).