I believe there are some benefit
sorand drawbacks which are needed to
see furtherconsidered.Generally, calculator is human's best friend
There can be many other devices that people think they are their best friend. Mobile phone is one such exmaple.
Obviously, learning arithmetic is needed.
Obviously, being able to perform arithmetic manually is an important task.This is because when a student could master the arithmetic, they could be smart people in basic calculation which could create a new formula which could be implemented in technology.
I don't find this sentence adding any value to your essay :(