Siāghat and Siāgh was a particular method of writing numbers which was created over time through the simplification of the writing of Arabic numbers. This method of writing, which was popular for financial registration over a thousand years, was used among various social groups in Iran for fiscal operations and daily calculations. At the time of the constitutional government, however, this method of Siāgh-Writing was replaced by a new one in budget. Iran’s “Books of income and expenditure” (Dafater-e dakhl va kharj-e mamlekati) was discarded. Instead, the budget-writing system was put to good use. The present article explores the social changes at the end of the Qajar period and the reasons for the gradual decline in Siāgh-Writing in order to answer the following question: Does this change take place of necessity and due to the presence and influence of the foreign counselors? Or does it originate in the views and ideas of domestic reformists?