*GUARANTEED ANSWER ✅* It’s foundational to student understanding across multiple topics in mathematics and science. In mathematics, they are central to developing concepts and skills related to slope, constant rate of change, and similar figures, which are all fundamental to algebraic concepts and skills. In the real world, ratios and proportions are used on a daily basis. ... Ratios and proportions are also used in business when dealing with money. For example, a business might have a ratio for the amount of profit earned per sale of a certain product such as $2.50:1, which says that the business gains $2.50 for each sale.