This reminds me of morning routine back in grade school called "Mad Minute" where we would be given a sheet containing 30 or 50 simple equations to solve. You'd

This reminds me of morning routine back in grade school called "Mad Minute" where we would be given a sheet containing 30 or 50 simple equations to solve. You'd have to complete it in a minute and the teacher would stopped grading at the first wrong answer so getting the first one wrong follwed by 49 correct answer would net you a score of zero. When I first transferred to that school I was terrible at it but I did get pretty good at it later on. I think it did a lot for my arithmetic skills.