A plan for integrating quantitative reasoning throughout an undergraduate core curriculum including the natural sciences, social sciences, and humanities is presented. Four interrelated aspects of quantitative reasoning are discussed: learning from data, quantitative expression, evidence & assertions, and quantitative intuition. Learning from data refers to the skills associated with collecting and analyzing data. Quantitative expression is the ability to use and comprehend quantitative language in a variety of contexts. Facility with evidence and assertions allows one to comprehend which conclusions may be reasonably drawn from a body of evidence. Quantitative intuition refers to heuristics that lead to a "feel" for numbers and other quantitative concepts. Several quantitative exercises are described. The general pedagogical orientation of the plan is student-centered and experiential.