As a part of mercantilism and government, numbers have grown to a primary level. People must cope with percentages, estimated life figures, lifetime rating calculations, per ounce costs, taxes, debts, and values on investments. All of this input information must be absorbed, processed, ordered, and made into sensible and usable data for normal living. Numeracy is needed for scientific and quantitative reasoning to understand reports, facts in the paper, and medical claims. Much that is publicly reported is flawed, but numerically illiterate readers usually fail to detect such problems.
Mathematical understanding is too important to be confined to the mathematics classroom.
Mathematics is the great equalizer, because virtually everything in our lives today is treated in a numerical manner, e.g. measures, prices, warranties, insurance restrictions. A numerically illiterate person is as handicapped in our society as one who cannot read. Critical thinking requires questioning all the conditions in a situation, properly using logic, statistics and graphing, and dealing with uncertainty. Critical thinking and numeracy are interdependent because a sound understanding of quantity and numeracy is necessary for precision in thinking. Here's a situation, think about it.