Very early calculators (8)
I believe the answer is:
abacuses
(Other definitions for abacuses that I've seen before include "Counters" , "they calculated" , "outdated calculators" , "Calculating devices" , "old computing devices" .)
I believe the answer is:
abacuses
(Other definitions for abacuses that I've seen before include "Counters" , "they calculated" , "outdated calculators" , "Calculating devices" , "old computing devices" .)