21. Billion Investment Holding's subsidiaries are involved in producing and trading in electronic calculators , translators and hand-held games. 22. When it was introduced in late 1969, it was one of the smallest electronic calculators ever produced commercially. 23. The number of machines produced increased constantly until the appearance of the electronic calculators in the early 1970s. 24. Instead, he returned with the new idea to produce electronic calculators , which were just coming on the market. 25. For the first time, proprietary electronic calculators were provided to CPA candidates for the two new accounting sections. 26. Critics later pointed to ABC's flaws when arguing that it was actually an electronic calculator , not a computer. 27. Since hand-held electronic calculators are designed by engineers rather than mathematicians, it became customary that they follow engineers'notation. 28. They settled in Dallas, Texas, where he was employed as a technician fixing typewriters, electronic calculators and computers. 29. Curtas were considered the best portable calculators available until they were displaced by electronic calculators in the 1970s. 30. The popularity of electronic calculators drew the traditional office equipment companies and the semiconductor companies into the market.
