Ключевые слова: accounting, add, addition, algebra, background, banking, black, budget, business, button, calculate, calculation, calculator, calculus, computer, count, digital, divide, division, education, electronic, equals, figures, finance, handheld, high, isolated, job, key, math, mathematics, modern, money, multiplication, multiply, number, numbers, object, office, plastic, plus, school, science, scientific, subtract, subtraction, technology, tool, white, work,