There were no calculators. Paper was expensive, and stone records were cumbersome. The entire numerical system was thought of differently…as some cultures didn’t even have counting numbers.
The only way to keep track of things was a 1 for 1 “trade-off”.
This “trade-off” nature really reflects prayer beads as you don’t need to know how to count, or have any number theory in order to say the rosary or chaplet.