Reply to this professionally "Good evening, when I think or percent I usually think of it only when it comes to my phone battery as I don't use percentages commonly in my day to day life. When I do have to use them I would prefer to think do them as ratios as that helps me better. The only shortcut I have for calculating percentages without a calculator is doing it in scratch paper. In my life experiences I feel that using percentages in my budget will be more helpful as it will help me spend my money wiser and also help me save it better. Only percents that I see in my daily life is my battery percent