Math For Kids Abacus Lessons Always Ready Everyday By Private Tutors Solving Problems With Cool Game
Step six. Move down the rows adding numbers. If a number becomes greater than ten, you move on to the next row. For example, if you add seven to one thousand two hundred and fifty four you would start with the four. Slide the four beads back down and slide the five beads down. Then push 4 beads back up. This gives you nine and you have used all your beads, but you have only added four plus five. You still need two more to make four plus seven. These two get added to the next row to the left. If this row adds up to be more than nine, you add what's left over onto the next row. Step seven. Continue moving across the rows until you have finished adding. To subtract, you follow the same procedure as addition, only moving from left to right instead of right to left.
Some interesting facts on the origins and history of the abacus reveal that an abacus was first used in the year two thousand four hundred BC by the Babylonians and was made from sand and pebbles. It is also known that in the first century in China and in India, an abacus with beads was recorded as being used. India also had the use of the abacus at this time. Sometime in the three thousand years between those two times the abacus was first used with beads. This was perhaps in Mesopotamia or Ancient Egypt. It is estimated to have been in Rome or in Greece at around the year three hundred BC.