Loops inside loops — grids, patterns, tables, and matching pairs
Interactive step-through animation — see how outer and inner loops run
Grids, triangles, multiplication tables, break behavior, and counting iterations.
Print a repeating number grid using nested loops.
Print the full times table for any number.
Print all (row, col) pairs for a grid.
Find all unique pairs from a list of items.
Variable names, break behavior, off-by-one errors, and debugging.