A fascinating story!
Chemistry, as we know it today, has its roots in ancient civilizations, with contributions from philosophers, alchemists, and scientists over thousands of years. Here's a brief overview:
Ancient...
27*39
First multiply 7*9=63 write '3' and take 6 as carry.
Then cross multiplication i.e. multiply '7*3'=21 and '9*2'=18 add '21+18+6(carry from first multiplication)' = 45....