|Animation of the inputs and outputs of a combination of logic gates that form a full adder. A full adder is used to perform the addition of numbers. It is constructed of two XOR gates, two AND gates and an OR gate. The system has three inputs, which split to carry the same input to more than one gate. The outputs of the earlier gates become the input of later gates. The inputs A, B and C in can be controlled by the user. The system has two outputs, called sum (S) and carry (C out). The logic table and the results of the addition are shown in lower frame. When inputs A, B or C is on (blue), the output is only to the sum. When two of the inputs are on, the output is the carry. When all three inputs are on, the output is the sum and the carry. This system performs the addition of the inputs, with off being zero and on being one. Multiple adders can be used to build a calculator, with the carry becoming an input of the next adder in the system, hence carrying the number to the next highest significant figure. See clip K007 7620 for an array of full adders in an electronic calculator.