Lesson 3: Addition using 10's complement

In Abacus we have only 5 beads on a column to count and operate numbers from 1 to 9. In that case, we are going to need the use of complements. We remember the complements in pairs. In this video, we are going to see the use of 10's Complement to do an addition. In case, we do not have enough beads we add 10 and subtract the 10's complement of the addend to do the addition. At the end of the, you will get to understand how using complementary numbers help in doing mental arithmetic.