Using an Abacus/Multiplication
Multiplication is, by definition, the addition of some number so many amount of times. Therefore, to multiply a number by a desired number requires the same principle.
To multiply:
- Display the original number.
- Think of desired multiplier.
- If multiplier has more than one digit, multiply by digits separately
- Add the original number however many times desired.
- Move to the next digit and repeat step 4 if multiplier has more than one digit.
Example: (4×5)
4=4 0000-|-0 -0000|-0 4+4=4×2=8 0000-|-0 0-000|0- 8+4=4×3=12 000-0|-0 00-00|-0 12+4=4×4=16 000-0|-0 000-0|0- 16+4=4×5=20 00-00|-0 0000-|-0
Here is another example with one number having two digits: (5×2.5)
5=5 0000-|-0 (0) 0000-|0- (5) 0000-|-0• (.0) 5×2=10 000-0|-0 0000-|-0 0000-|-0•
5×0.5=2.5 0000-|-0 00-00|-0 0000-|0-•
10+2.5=12.5=5×2.5 000-0|-0 00-00|-0 0000-|0-•