One of the seven processes is Mental Mathematics & Estimation (see some thoughts about this process here). One thing we've done at our school is really tried to eliminate the reliance on a calculator, especially for Algebra & Number. I'm interested in what other's think about this... has anyone else restricted calculator use?
I'm also looking for more ideas on how to promote Mental Math & Estimation. Anyone have any thoughts?
I encourage my class to not rely or use their calculator. When discussing a question or working through an example I try not to use a calculator to model to them the importance of understanding an knowing the basic facts.
But many struggle with the times tables or working with integers. With those students I encourage them to use the calculator as a tool for them to be successful.
When we do problem solving, I always have the students think of an estimate prior to solving the problem. They can use this as a check and it encourages them to really understand what is occurring and not just remembering a procedure. I also ask them if the answer we have makes sense? Are you OK with that answer? Again, so they do not just rely on what their calculator "told" them.
In the higher levels, especially the -1 stream, I will give quizzes or portions of a test where a calculator cannot be used. I do this more at times, so they do not just use the functions of the calculator to find the answer. They need to show me they understand.
These are my thoughts. Hope it helps.
I guess it would depend on your purpose of estimation. If used to prove a calculation correct, then spend a little time on it. Otherwise, in this day and age with the use of technology, spending time on this concept would only slow the student down when they are moving on to higher mathematics. The estimation process should have been covered in JH. As far as mental math goes, encourage the student to not depend so much on the calculator as it only slows their progress. Show shortcuts in calculating.