Hello, recently I am having some issues in math related problems. Most of the other tag problems like implementation,brute force,games,number theory problems seems to be ok to me.But when it comes to math related problem I most of the time do it in bruteforce approach or implementation result is obvious. Most heart breaking part is even 800-900 rating problems in math becomes harder while contest time sometimes. If A problems getting 2-3WA or takes longer than 10-15 minutes then it's really hard to focus on the next questions cause of depressions. And it's not like I haven't solve math related problems so often.But when it comes to contest time simple formula seems to be a big of a deal and it's really hard for coders like me.Please suggest me some sites from where I can enrich my thinking capabilities in math and has some decent problems. Thank you.

Well I guess you can choose the math tag here on Codeforces and start solving from 800 level in problems

I already did solve a number of problems related math which is more frastrating to me as I solved quite number of problems but in contest their are some other shits happening.800-900 problems 3 page already green but in contest I am strugling with easy ones.Also in mixed tag problems I am facing trouble in specific "math" section. I think may be my basic is not so good enough still now .So I want suggestions for this.