The Romans once conquered most of the then known world; but they took little interest in the art of mathematics. They used their fingers or the abacus to calculate, the abacus, to which there were also help boards. If Kaiser Augustus before 2000 Years wanted to have his empire measured, he had to get experts from Alexandria for this.
Centuries after the fall of Rome, fingers were still counted in Europe, up to about 1100 n. Chr. But the Romans and also the other peoples, who counted with their fingers until the Middle Ages, could only add and subtract using this method.
Below we show an easy way, how to use finger math to calculate numbers from 6 to 9 can multiply:
Each finger means a number from 6 to 10 (see diagram).
To multiply, we had the tips of the two number fingers together. (In the picture we multiply 8 by 8.) We count fingers, touch each other, and those below; that is the number of tens. Then we count the fingers, located above the touching fingers, each hand for itself. You now multiply the number of these fingers on the left hand by those on the right hand and you have the ones. Add tens and ones together, gives the result.