| 摘要 |
PURPOSE:To facilitate detailed accounting with high reliability even if the amount of shopping reaches a high price by erasing part of plural recording symbols so as to decrease the residual every time the card is used at shopping. CONSTITUTION:A card 1 is recorded while a high price symbol 3 and a low price symbol 4 are divided into two physically different kinds. The unit of the low price symbol 4 is Z and the minimum amount of memory W at one shopping in use is expressed as W=wZ (w is an integral number of >=6), then a storage section 13 distinguishing the high price symbol 3 and the low price symbol 4, a storage section 14 for Z and (w), and a storage section 15 for a maximum integral number n of mn<=w, where (m) is either a maximum integral number m, or a minimum integral number m2 as m1<w/w<1/2>+1<m2, are provided and X=nZ in using (n) is erased as the unit amount of the high price symbol 3. Thus, at every shopping, part of plural recording symbols is erased to decrease the residual amount as a coupon and even if the amount of shopping reaches a high price, the detailed account is facilitated with high reliability. |
