The first time I saw common core was for simple subtraction problems and my brain had to take a long time to process because it was just over complicated. For people who aren't naturally good at math it can really confuse and hurt students academically. I think that a person should do math the best way for them. If common core works better for some people then go for it...but if the old methods like how I was taught are better for you to comprehend then you should be allowed to use that way instead.