Compiled by Joan O’Hagan.
This list includes many maths sources and resources which I have found useful.
It includes a small number of YouTube videos, which may carry some advertising.
A few sites require you to register before you can access the full site. Almost all the resources are free.
Title  What’s it about?  Location 
ALM  Adults Learning Mathematics is an international forum for researchers and practitioners. Founded in Birmingham, UK in 1992. Annual conference, with alternate conferences inside / outside Europe. Friendly and stimulating group.  http://www.almonline.net 
ATM  Association of Teachers of Mathematics: membership organisation with about 4000 teachers, mainly primary and secondary. Treasure trove of learning resources. Some free, some available only to members.  http://www.atm.org.uk 
BBC Sites  Learner materials, including mathematics videos, e.g. why subtraction or fractions are useful; quiztype skills checks and games.Skillswise is useful for revision of Level 1 work.
Bitesize is GCSE material. 
http://www.bbc.co.uk/skillswise and
http://www.bbc.co.uk/schools/gcsebitesize/maths/

Countdown  Online versions of the TV game  http://nrich.maths.org/6499http://www.ilovemathsgames.com/flashfiles/countdownem.swf 
ILIM Mostly Algebra  The ILIM “Standards Unit box”.Contents are available online. Mostly GCSE.
Rich source of materials you can use directly with learners, and materials that focus on supporting your professional development. 
http://www.nationalstemcentre.org.uk/elibrary/maths/collection/489/mostlyalgebramaterials 
ILIM Mostly Number  http://www.nationalstemcentre.org.uk/elibrary/maths/collection/485/mostlynumbermaterials  
ILIM Mostly Other  http://www.nationalstemcentre.org.uk/elibrary/maths/collection/931/others  
ILIM Mostly Shape and Space  http://www.nationalstemcentre.org.uk/elibrary/maths/collection/492/mostlyshapeandspacematerials  
ILIM Mostly Statistics  http://www.nationalstemcentre.org.uk/elibrary/maths/collection/493/mostlystatisticsmaterials  
Improving Learning In Mathematics (ILIM)  “The Standards Unit box”. Contents are available online. Mostly GCSE.  http://www.nationalstemcentre.org.uk/elibrary/maths/collection/282/improvinglearninginmathematics 
Inquiry Prompts  Activities to prompt exploration of particular concepts. Includes prompts for number, algebra, geometry  http://www.nationalstemcentre.org.uk/elibrary/collection/1830/inquirymaths 
LSIS Embedding Functional Skills  Scroll down for a series of videos about vocational and functional skills (including mathematics) teachers working together  http://tlp.excellencegateway.org.uk/tlp/fs/fsresources/cpd_act_2.php 
LSIS Functional Skills resources

Learning materials and cpd materials searchable by subject (including mathematics), vocational area, level. Also has a checklist to help you evaluate the resource. Most learner materials come with suggestions for use.  http://tlp.excellencegateway.org.uk/tlp/fs/fsresources/library.php 
Math class needs a makeover  A challenging, 12 minute video suggesting that we teachers are sometimes our own worst enemies. TED talk by Dan Meyer.  http://www.ted.com/talks/dan_meyer_math_curriculum_makeover.html 
Maths visualisations  A delightful animated exploration of number patterns.  http://www.datapointed.net/visualizations/math/factorization/animateddiagrams/ 
Maths2art  Created by a teacher to approach mathematics through art. Includes teaching ideas and resources  http://www.maths2art.co.uk/index.htm 
MEI  offers maths teachers a range of cpd opportunities and resources. Includes for example materials to support teachers to develop their personal maths skills to GCSE level.  http://www.mei.org.uk 
Mr Barton  Mathematics tricks, jokes and some serious stuff: aimed at teachers, parents, students (mostly secondary)  http://www.mrbartonmaths.com/ 
National STEM Centre  Vast treasure trove for Science, Technology, Engineering and Maths teachers.  http://www.nationalstemcentre.org.uk 
NCETM Essentials  The NCETM website is huge. The “Essentials” page groups ideas under headings like “Functional maths” or “GCSE resits”.  https://www.ncetm.org.uk/resources/35530 
NCETM selfassessment tool  Online tools to help you check your understanding of the mathematics you are teaching and explore ideas on how to develop your practice.  https://www.ncetm.org.uk/selfevaluation/ 
NCETM Workplace Mathematics  Videos and resources related to the maths used in various jobs:Architect  https://www.ncetm.org.uk/resources/13955 
nrich  Rich mathematical tasks for learners at all levels. Categorized by school stages but fairly easy to “read across’ to adults’ needs. Brilliantly challenging. Lots of “low threshold, high ceiling” tasks.  http://nrich.maths.org/public/ 
Numberphile  New website with youtube videos “about number and stuff”. Recommended by Plus Magazine which is part of the Millennium Maths Project.  http://www.youtube.com/numberphile 
Plus Magazine. Part of the Millennium Mathematics project  Articles and resources about relating mathematics to art / medicine / cosmology / sport.  http://plus.maths.org/content/ 
Starters of The Day  a new start for every day?  http://www.transum.org/software/sw/starter_of_the_day/index.htm 
Street Maths and School Maths  a book discussing differences between the maths people (can) do in formal classrooms and in real life. Includes discussion with experienced and inexperienced carpenters about how they use mathematics to help with reallife tasks.  Nunes, T., Schliemann, A., Carraher, D. , 1993, Cambridge University Press 
Teaching and Learning Functional Maths  Thoughtprovoking contextualized and “pure” maths materials, together with guidance on writing your own.  http://www.excellencegateway.org.uk/169932 
TES  Resources developed by teachers, mostly schoolbased. Free.  http://www.tes.co.uk/teachingresources/ 
The ultimate puzzles site  Mathematical puzzles site.  http://www.puzzle.dse.nl/index_us.html 
Thinking Through Maths online  Most of the contents of the “TTM yellow ring binder” aimed at mathematics teachers are now online. Learner materials with discussion of how to use them, cpd materials. You’ll need to log on / register. Focussed on learners working at Entry level / Level 1.  https://www.ncetm.org.uk/onlinecpdmodules/ttm/ 
Transum  free resources. Starters, Investigations, selected youtube maths videos. Designed for schools but useful in any sector  http://www.transum.org 
Twentyfour problem  A game to support mental manipulation of numbers. Harder than it looks (or maybe my number skills need a bit of work?)  http://www.24theory.com 
What’s The Point Of Maths?  Real life uses of maths, much of it around GCSE level, but even if you are working at students preGCSE you may find this interesting.  http://www.nationalstemcentre.org.uk/elibrary/maths/resource/6908/whatsthepointofmaths 
What’s the point of…?  Teaching resource produced by “More Maths Grads”, a project which aimed to increase the number of people studying maths (particularly in HE).
“What’s the point of….?” Has some material very useful around GCSE level. 
http://www.moremathsgrads.org.uk/home.cfm 
WisWeb  Applets on a wide range of topics at a wide range of levels  http://www.fi.uu.nl/wisweb/en/ 