Teaching kids to use calculators DOES increase their problem solving ability. They can produce the same result as someone using paper. If the problem's really advanced, they may have to use brackets correctly too. You teach the same logic whether it's on paper or not, just instead of shuffling numbers in your head, a system that's BETTER at it is doing it instead.
But the issue is, you've added the Calculator dependency to the Kid program. Whether or not that's an issue depends on whether Calculator is a well maintained and dependable project.
On the other hand, there are downsides to NOT using the easier Calculator library, and writing all the code from scratch (i.e. Memorising Mathematics systems and practicing them enough to use them at any reasonable speed) — 1) storage space and using up brainpower / focus storing micro numbers, when you could be focusing on the bigger picture algorithm, 2) speed, the Calculator library is optimised and written by experts, 3) bugs, the Calculator library is well tested, whereas it's easy for anyone to make simple arithmetic mistakes.
But the issue is, you've added the Calculator dependency to the Kid program. Whether or not that's an issue depends on whether Calculator is a well maintained and dependable project.
On the other hand, there are downsides to NOT using the easier Calculator library, and writing all the code from scratch (i.e. Memorising Mathematics systems and practicing them enough to use them at any reasonable speed) — 1) storage space and using up brainpower / focus storing micro numbers, when you could be focusing on the bigger picture algorithm, 2) speed, the Calculator library is optimised and written by experts, 3) bugs, the Calculator library is well tested, whereas it's easy for anyone to make simple arithmetic mistakes.