When adding a column of multiple binary numbers, our sums will often generate more than one carry to the next column. An easy way to calculate the correct number of carries is to cross out pairs of 1s in the current column and mark a carry in the next column for each pair. Remember that each time two 1s are added, they generate a carry to the next column.

The animation below demonstrates how to add the numbers 111

_{2}, 110_{2}, 1101_{2}, 101_{2}, and 1110_{2}. Click on the "Start Tutorial" box to view the animation.