Carry-save adder

Carry-save adders are used to make adding numbers faster. They work by first breaking up a big number into three smaller numbers. Then all three numbers are added together at the same time. The first two numbers added together will make a result that includes both the number that was added, plus the "carry", which is any extra number that the first two numbers added together resulted in. The carry is then added with the third number, so that all three numbers are added together. This way is much faster than adding all three numbers one at a time.