(16) Cranmer Abacus- Subtract by 8-learn the rules – YouTube
https://www.youtube.com/watch?v=OG7gNWzZHhg
Educational Services for Blind/Low Vision -Specialized Instruction in Technology/Braille/Nemeth and other Blind skills
https://www.youtube.com/watch?v=OG7gNWzZHhg
https://www.youtube.com/watch?v=WJZv5WG9PJs
https://www.youtube.com/watch?v=NpYWnuGmChM
https://www.youtube.com/watch?v=0vcYF7iuBM8
https://www.youtube.com/watch?v=Xe31vCLg8gI
https://www.youtube.com/watch?v=3rJs94wK_Po
https://www.youtube.com/watch?v=gIlPb33w9HY
https://www.youtube.com/watch?v=md0osGVpb6I
https://www.youtube.com/watch?v=5ymxWrUCtEE
https://www.youtube.com/watch?v=TBcBQ_4KYwo