you must be very good with number sense skills which is an intuitive feel for numbers and their

Due ASAP. 8-17-08. will pay bonus. Please answer the fpllowing two questions.Please read the following article (see link) about the debate of using calculators. Please share your comments about the article with all of us. Do you agree with the author?
http://www.unc.edu/depts/cmse/MSEdNC/calculators.html
One of the disadvantages of calculators is that people are forgetting their estimation skills. There are many instances in our daily lives where estimating is an essential skill since the exact figures are not necessary to solve a particular problem or perform a task. Having an approximate figure is sufficient to provide an idea or solution of what is intended to solve. To be good doing estimates, you must be very good with number sense skills which is an intuitive feel for numbers and their relationships.
What do you think? What you do more often: estimating or calculating exact answers? Can you provide real-life examples where estimating is more important than the exact answer?