Well almost the same in my case as I have been using calculator for 1 and a half yrs now... but for getting a grasp in maths, I think u should go through the topics covered in the respective exam which you'll be giving and then go on solving many questions in a go... initially you will give a lot of time just for solving one question but after solving 15 questions or so you'll possibly get into the flow and this way you should also practice for non verbal reasoning.

Hope this helps!