传动皮带类商品是卷圈形存放的。零售商店一般按其长度计价出售。月末盘点商品结存数量时,如果仍按尺量办法进行清点,不但手续麻烦,费时费劲,而且稍不留心往往易出差错。对这种商品的盘点,运用“等差数列”方法,可达到既准又快的目的。现将其具体方法介绍如下:等差数列公式是((a_1+an)n)/2 Drive belt products are roll-shaped storage. Retail stores are generally sold at their length. Inventory inventory balance at the end of the month, if still measured according to the measure, not only the procedures cumbersome, time-consuming and hard, and careless is often easy to go wrong. The inventory of such goods, the use of “arithmetic sequence” method, can achieve the purpose of both fast and accurate. The specific method is introduced as follows: Equal number sequence formula is ((a_1 + an) n) / 2