How to Use the Soroban
Basic Rules:
➊ Each column represents a place value (from right: units, tens, hundreds)
➋ Upper bead (heaven) = 5 units
➌ Lower beads (earth) = 1 unit each
Addition:
1. Set the first number using beads
2. Add the second number starting from rightmost digit
3. Carry over excess beads to next column
Subtraction:
1. Set the larger number first
2. Subtract starting from rightmost digit
3. Borrow from next column if needed