Disappeared as unnecessary.
Things tend to become obsolete and irrevocably become a thing of the past. Much of what was used every day in the USSR is today considered a curiosity. For example, now not every person knows what an abacus is and how it works.
Meanwhile, in Soviet times, neither adults nor children could do without them. Abacus could be seen primarily in stores or at enterprises where at least some computing operations were carried out.
Accounts were divided into office and school accounts. They were no different from each other, except in size. They were used for such simple arithmetic operations as addition and subtraction.
Until the early 80s, the ability to work with a simple instrument was part of the compulsory school curriculum. This requirement was then abandoned, but nevertheless, the scores finally disappeared only in the 90s.
