The purpose of this utility model, can be arbitrary shelves of abacus free and show independently with regard to being to make from negative 1 to negative 9 arbitrary negative sign indicating number, make any negative computational problem in the algebra, can be on abacus computing freely, and the advantage that can show with rechoning by the abacus in the positive number field is the same, for the calculating of any negative, calculate all more than being height with written calculation even than computing velocity with electronic calculator with rechoning by the abacus.So just might make the teachers and students of junior middle school, senior middle school and even institution of higher learning think a kind of desirable tool of calculating, be so fond that will not let out of one's hand.So establish and stood the basis for creation education theory with Chinese characteristics, teaching method, teaching material, teaching aid, showing our the Huang Yan descendants of a nobleman has the ability of making unremitting efforts to improve oneself, standing proudly in the family of nations. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) Filing date Publication date Application filed by 张枕善 filed Critical 张枕善 Priority to CN 89200396 priority Critical patent/CN2055267U/en Publication of CN2055267U publication Critical patent/CN2055267U/en Status Withdrawn legal-status Critical Current Links Inventor 张枕善 Original Assignee 张枕善 Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Withdrawn Application number CN 89200396 Other languages Chinese ( zh) Google Patents Multi-purpose abacus with positive and negative beadsĭownload PDF Info Publication number CN2055267U CN2055267U CN 89200396 CN89200396U CN2055267U CN 2055267 U CN2055267 U CN 2055267U CN 89200396 CN89200396 CN 89200396 CN 89200396 U CN89200396 U CN 89200396U CN 2055267 U CN2055267 U CN 2055267U Authority CN China Prior art keywords negative abacus calculation pearl positive Prior art date Legal status (The legal status is an assumption and is not a legal conclusion. Google Patents CN2055267U - Multi-purpose abacus with positive and negative beads CN2055267U - Multi-purpose abacus with positive and negative beads
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