Number crosswords are puzzles that combine elements of traditional crosswords with numbers. Instead of filling in words based on clues, players fill in a grid with numbers that correspond to specific clues. Each number represents a unique answer, and the clues can involve mathematical operations, sequences, or logic. These puzzles often feature a grid layout similar to standard crosswords, with numbered squares indicating where answers should go. Players must use their reasoning skills to deduce the correct numbers based on the provided clues, making number crosswords a fun and challenging activity for puzzle enthusiasts and math lovers alike.