Calculus adds infinite tiny pieces to find big answers

Integral calculus, developed by Isaac Newton and Gottfried Wilhelm Leibniz around 1665-1676, calculates the total area under a curve by summing countless infinitesimally small areas. This powerful math technique allows us to precisely measure things impossible to calculate directly, like the exact area under a complex curve. For instance, it reveals the area under y = x² from 0 to 1 is exactly 1/3 square units.