My Flying Colors video 1

https://youtu.be/mb72Pp8t7IE

My Flying Colors video 2

https://youtu.be/rpxBLtL9yV0

My Flying Colors video 3

https://youtu.be/v1vLqTvIfyc

My Flying Colors video 4

https://youtu.be/9TSt3-JH0DA

The exact working of Abacus

https://youtu.be/CvsnftXXKdw