In the world of mathematics, entry into calculus comes through practice in trigonometry, algebra, limits, and exponential/logarithmic functions: "pre-calculus." Such practice is necessary to understand calculus, the study of measuring infinitesimal change. According to 1980s psychologist Howard Gardner, learners assimilate information using a variety of senses and abilities: musical-rhythmic, visual-spatial, verbal-linguistic, logical-mathematical, bodily-kinesthetic, interpersonal, intra-personal, and naturalistic, by name. For visual learners, a flow-chart mapping the proper math to apply to a problem would help them solve it.