Linked from
The 17 pages that link to Addition, each with the reason it gives.
Natural numberRelated: Repeated successor steps define addition on natural numbers.
AbacusRelated: Bead movements add quantities, with exchanges between columns when a place fills.
Distributive propertyRelated: Distribution acts on sums by separating their addends.
PerimeterRelated: Polygon perimeter is calculated by adding the lengths of its boundary segments.
OneRelated: Adding one increases an integer by its immediate successor step.
Number lineRelated: Adding a number corresponds to a directed shift along the line.
0 (number)Related: Zero is the additive identity because adding it changes no integer.