In response to yesterday's post about MathsLinks a handful of folks reminded me via email and Facebook of another good place for teachers to find mathematics resources. That place is NRICH which I initially reviewed almost eight years ago and then again five years ago. Upon revisiting NRICH today I found that it is still a great place to find math resources.

NRICH is a provider of mathematics curricula and lesson plans covering everything from basic addition through advanced algebra and geometry. NRICH has sections for teachers and sections for the students. The teacher sections contain lesson ideas and plans. Some of those plans correspond to activities students can do online while others are entirely offline activities. The student sections of NRICH are intended to be mostly self-guided. Students will find interactive games and also find some challenge activities that are not games but instead prompt students to apply their math skills to ask questions and solve problems like this one.

NRICH offers dozens of posters to download and print. Each of the posters displays a mathematics "trick" or challenge question. Teachers can download and print any of the posters in the collection. Each poster in the collection is linked to a problem page that contains notes for teachers using the posters.