Keywords: abacus hat beads addition add sum computation indoor I'm now adding 5 in the 5th position from the left. This is done in 2 steps: add 10, subtract 5. In this step I add 10 by adding 1 in the 4th position from the left. CC0 waiver: To the extent possible under law, I waive all copyright and related or neighboring rights to this work. I'm now adding 5 in the 5th position from the left. This is done in 2 steps: add 10, subtract 5. In this step I add 10 by adding 1 in the 4th position from the left. CC0 waiver: To the extent possible under law, I waive all copyright and related or neighboring rights to this work. |