Nrich publish new problems every month. Why not try and get a solution published on their website?
There is a menu specifically for students. You can sign up for an Nrich student newsletter if you want to be notified of new developments on the site. If you have not tried Nrich problems before you may find their recommended starter problems good to try. You can search for problems by topic if you wish.
Signing up to Brilliant (including an easy option for sign in for Facebook users) will allow you to join an international community and get free weekly, personalised problems. Questions at various levels are available. (See this post for further information).
For a problem to exercise your mind every day try the Mathematical Association of America’s Minute Math. Click on ‘Interactive version of the problem and solution’ to get a hint, you can also see a solution.
For weekly problems try the challenges from the University of Mississippi.
Four problems are set every week.
The Problem of the Week and Algebra in Action challenges are open to anyone from anywhere of any age! The Middle School Madness and Elementary Brain Teaser problems are for school age children, Middle School Madness for grade 8 (age 14 and under), the Elementary Brain Teaser for grade 6 (age 12 and under). If you submit a correct solution by the deadline that week your name will be published on the website. You might even win a T-shirt!
- Group A – 3rd and 4th graders – UK Year 4, Year 5 ages 8-9 and 9-10
- Group B – 5th and 6th graders – UK Year 6, Year 7 ages 10-11 and 11-12
- Group C – 7th and 8th graders – UK Year 8, Year 9 ages 12-13 and 13-14