Ключевые слова: abstract, add, addition, analysis, background, bad, block, business, calculate, calculator, choice, choose, compare, comparison, con, concept, contrast, correct, cross, decision, difference, element, feedback, flat lay, good, graphic, icon, mathematical, mathematics, minus, negative, no, opposite, plus, positive, pro, reduce, set, sign, solution, strategy, subtraction, success, symbol, versus, vs, wood, wooden, yes,