In maths there are situations you should use the calculator. If there is a complex calculation or some thing like that you can use it. But for simple calculations you should use your own thinking power. If you didnt use you brain for calculation since you have a calculator it would decrease your capacity and power of the brain. The best method is to use the calculator as a confirmation mode. Then you can solve by brain and check by calculator.

I see a decline in the ability of my students over the past 30 years as an educator in the science class with their basic math skills. My students cannot figure out averages, percentages, do basic equations, multiply or divide, without a calculator. Therefore, I believe that calculators shouldn't be used until college in a classroom so that students learn basic math.

I think using a calculator is just like using any other technology, there has to be a balance.  Yes, using a calculator has many benefits.  It can speed your work and improve your accuracy.  However, consistently depending on a calculator could prevent you from being able to perform even the simplest calculations without technological assistance.

The benefits of using a calculator include being able to see patterns without having to do the tedious calculations, the ability to work on "real-world" problems which frequently involve large numbers or lots of decimal places, and freeing your mind to concentrate on the concept instead of the arithmetic.(Its the process that is important, not the answer). That said, overuse of a calculator can lead to silly errors (if you cannot estimate the answer you might accept a bizarre calculator answer), the inability to recognize common errors, and as a previous post points out if you do not exercise this aspect of your mind it will atrophy. Calculators are a great tool (try doing logarithms without one) but are frequently overused.

I agree that using a calculator is not "wrong." A person must be able to use the calculator correctly in order to properly calculate. That said, I do believe that there are certain things a person should be able to do without a calculator: simple addition, subtraction, multiplication, and division.

I don't really think there's anything wrong with using a calculator as long as you would know what to do without one.  Arithmetic is not the really important and difficult part of math anyway.  Using a calculator helps you do the "busy work" of math, but it doesn't do the hard part for you.  Therefore it's more of a good thing than a bad.