I just came across a forum on which on of the contributors has so kindly listed some numeracy websites. Take a look here and have a look around the site. Just in case that link is no longer active, here is a copy of the listing.
www.algebra-help.co.uk
www.allmath.com
www.angliacampus.com/public/sec/maths/fract/index.htm (fraction activity)
www.argonet.co.uk/oundlesch/mlink.html
www.argosphere.net
www.awaywithmaths.com **
www.bbc.co.uk/learning
www.beam.co.uk
www.bigchalk.com
www.byteachers.org.uk
www.cafod.org.uk (numeracy games)
www.chalkface.com
www.channel4.com/learning
www.cleo.ucsm.ac.uk/content/topten/
www.learningbeyond.net/
www.bbc.co.uk/education/revisewise/index.shtml
www.bbc.co.uk/education/mathsfile/index.shtml
www.picadome.fcps.net/lab/currl/math/default.htm
www.school.discovery.com/homeworkhelp/webmath/
www.thelighthouseforeducation.co.uk/numeracy/default.htm
www.skillstrainer.co.uk/
www.curriculumonline.gov.uk/Curriculum%20OnLine/default.htm
www.bbc.co.uk/education/megamaths/
www.teachingtime.co.uk
www.teachingtables.co.uk
www.primarygames.co.uk
www.ineractive-resources.co.uk
www.cleo.ucsm.ac.uk/teachers
www.slamnet.org.uk
www.active-maths.co.uk
www.nces.ed.gov/nceskids/graphing/
www.dfee.org/flash.html
www.numeracysoftware.com/
www.ejad.best.vwh.net/java/b10blocks/b10blocks.html
www.arcytech.org/java/integers/
www.mathematics.hellam.net/
www.mathsroom.co.uk/levelA-C.htm
www.tygh.co.uk/tan/tan.htm
www.mathfactcafe.com (Maths worksheets generated)
www.mathslessons.co.uk (Great range of level 4 and 5 maths worksheets)
www.mazworks.co.uk
www.nelsonthornes.com
www.mathshere.co.uk – games/puzzles
www.comap.com
www.convert-it.co.uk
www.cut-the-knot.com
www.economics-education.co.uk (monkey number finger puppets)
www.edhelper.com
www.educate.org.uk
www.educationplanet.com
www.educationworld.co.uk
www.eduweb.co.uk
www.e-gfl.org/e-gfl/curriculum/resource/pss.cfm?subject=Mathematics
www.emaths.co.uk
www.emaths.co.uk/Interactive.htm
www.enc.org
www.ex.ac.uk/cimt
www.ex.ac.uk/cimt
www.footee.net
www.fours.co.uk
www.free.thebigbus.com/free/resources/maths/index.htm
www.funbrain.com
www.funmaths.com
www.grimagic.com
www.hamilton-trust.org.uk
www.happypuzzle.co.uk
www.jcutting.freeserve.co.uk/page3.html
www.justforteachers.co.uk
www.lastminutelesson.com
www.learn.co.uk
www.lessonplanspage.com
www.madras.fife.sch.uk/maths
www.mape.org.uk/activities/index.htm
www.mathacademy.com
www.mathagonyaunt.co.uk
www.mathsforum.org
www.mathsguru.co.uk
www.maths-help.co.uk
www.mathsisfun.com
www.mathslessons.co.uk/resources/resources.htm
www.mathslink.co.uk
www.mathsnet.net
www.mathsnet.net/mec
www.mathsonline.co.uk
www.mathsonline.co.uk/nonmembers/wrkshtlby/wshumber/index.html
www.mathspere.co.uk
www.mathsphere.co.uk/Resources/Resource_Games.shtml (collection of free board games)
www.mathsroom.co.uk
www.mathsyear2000.org
www.mathszone.co.uk
www.mepp.net
www.metric.ma.ic.ac.uk
www.mmp.maths.org
www.multiplication.com
www.murderousmaths.co.uk
www.nrich.maths.org.uk/public/index.php
www.nrich.maths.org.uk/public/index.php (higher achievers)
www.nrich.org.uk
www.numeracy.co.uk
www.n-yorks.net/curriculum/subjects/maths/info.html
www.nzmaths.co.nz
www.oxted.surrey.sch.uk/ring
www.pass.maths.org
www.perfect-times.co.uk
www.pifactory.co.uk
www.pipage.fsnet.co.uk
www.plusmaths.org
www.primaryresources.co.uk/maths/maths4a.htm
www.primaryworksheets.co.uk
www.school.discovery.com/brainboosters (Lots of brain teaser/problems mainly for H/A)
www.tes.co.uk/teacher/brainteasers/index.asp (Good for extension work)
www.schoolmaster.net
www.school-resources.co.uk
www.schoolsnet.com
www.schoolzone.co.uk
www.sitesforteachers.com
www.smilemathematics.co.uk
www.subtangent.com
www.tctrust.org.uk
www.teachersfirst.com
www.teachingideas.co.uk/maths
www.teachingideas.co.uk/maths/contents2.htm
www.teachingtime.co.uk/clock
www.techlar.com/fractals
www.timetoteach.co.uk
www.topmarks.co.uk
www.ukmt.org.uk
www.waldomaths.com
www-groups.dcs.st-andrews.ac.uk/~history/External/Westfall_list.html

http://www.ngfl-cymru.org.uk/vtc-home/vtc-ks1-home/vtc-ks1-maths(2).htm
http://schools.dk.com/static/lessonplans/lp_ks1_maths.html
http://www.lancsngfl.ac.uk/curriculum/math/xtras/numberrhymes/rhymes.htm
http://www.numberlinelane.co.uk/
http://www.teachingtime.co.uk/draggames/y1atod.html
http://www.teachingtime.co.uk/draggames/y2atod.html
http://www.dltk-teach.com/
http://www.enchantedlearning.com/themes/123.shtml
http://www.firstschoolyears.com/numeracy/index.htm
http://www.ks1resources.co.uk/page10.html
www.primaryresources.co.uk
www.funbrain.com
http://www.standards.dfes.gov.uk/numeracy/publications/planning/12848/375343
http://www.amathsdictionaryforkids.com/
www.counton.org
http://www.pdictionary.com/
http://oswego.org/ocsd-web/games/mathmagician/cathymath.html
http://www.coxhoe.durham.sch.uk/Curriculum/Numeracy.htm
http://www.lastminutelesson.co.uk/pdfs/number_ks2_cm18_113.pdf
http://www.primaryideas.co.uk/index_files/numeracy.html
http://www.train.stockton.gov.uk/pages/viewpage.asp?uniqid=1551
http://www.senteacher.org/main/print.php
http://www.aaamath.com
http://nrich.maths.org/public/index.php
http://www.primarygames.co.uk/pg2/splat/splatsq100.html
http://www.primarygames.co.uk/pg3/topspot/worksheet/topspotWS.html
http://www.mathsnet.net/cruncher/numbergrid.swf
http://www.standards.dfes.gov.uk/primary/publications/mathematics/itps/
http://www.ncaction.org.uk/subjects/maths/index.htm
http://www.nc.uk.net/webdav/servlet/XRM?Page%2F@id=6004&Session%2F@id=D_Qw0lSq78xr7tiA9D43Hm&Subject%2F@id=22
http://www.interactive-resources.co.uk/
http://www.crick.northants.sch.uk/Flash%20Studio/cfsmaths/cfsmaths.htm
http://csfsoftware.co.uk/products.htm
http://el.media.mit.edu/logo-foundation/
http://www.aaamath.com/
http://www.adrianbruce.com/index.html
http://www.coxhoe.durham.sch.uk/Curriculum/Curriculum.htm
http://www.emteconline.co.uk/
http://www.jamesbancrofteducation.net/
http://www.mathsphere.co.uk/Resources/Resource_Puzzles.shtml
http://www.senteacher.org/main/print.php
http://www.timestables.org.uk/cgi-bin/cp-app.cgi
http://www.ucl.ac.uk/SLAIS/rob-miller/lectures/P033/examples/squareNumbersForm.html
http://tre.ngfl.gov.uk/uploads/materials/18172/NGfL%20Excel%20Model.xls
http://mathforum.org
http://tlfe.org.uk/numeracy/units/placevaluelessons.htm
http://www.databases.dft.gov.uk/primary/list?subject=ICT&year=1
http://www.topmarks.co.uk/interactive.aspx#mathsks1
http://www.time-for-time.com
http://www.teachingandlearningresources.co.uk/funmaths.shtml
http://www.sparkisland.com/public/free_activities/xybok_racing/index.html#
http://www.numbergym.co.uk/ng_activities.html
http://www.mathsisfun.com/shape_space_measure.html
http://www.mathsisfun.com/number_algebra.html
http://www.mathsisfun.com/data.html
http://www.mathsisfun.com/mathsmisc.html
http://www.mathsisfun.com/puzzle.html
http://www.bbc.co.uk/schools/revisewise/maths/number/
http://www.bbc.co.uk/schools/revisewise/maths/data/
http://www.bbc.co.uk/schools/revisewise/maths/shape/
http://www.bbc.co.uk/schools/revisewise/maths/mental/
http://www.amblesideprimary.com/ambleweb/mentalmaths/Calculator.html
http://mathforum.org/alejandre/frisbie/pictogram.html
http://www.wiganschoolsonline.net/curriculum/resources/index.htm
http://www.mathagonyaunt.co.uk/mathFrameset.html
http://www.mape.org.uk/curriculum/maths/maths.htm
http://www.resourceshop.co.uk/rnumeracy/rnumeracy.htm
http://www.schoolzone.co.uk/resources/learninggame/mathslearninggames.asp
http://www.kevinsplayroom.co.uk/
http://www.ngfl-cymru.org.uk/vtc-home/vtc-ks2-home/vtc-ks2-maths(2).htm
http://schools.dk.com/static/lessonplans/lp_ks2_maths.html
http://www.oswego.org/ocsd-web/games/StopTheClock/sthec1.html
http://www.primarygames.co.uk/pg3/topspot/worksheet/topspotnegWS.html
http://www.teachingtime.co.uk/draggames/y3atod.html
http://www.teachingtime.co.uk/draggames/y4atod.html
http://www.teachingandlearningresources.co.uk/learningnumeracy.shtml
http://www.perfect-times.co.uk/
http://www.topmarks.co.uk/?Subject=16
http://www.abcteach.com/Math/mult1.htm
http://www.amblesideprimary.com/ambleweb/numeracy.htm
http://www.aplusmath.com
http://www.mathsonline.co.uk/nonmembers/gamesroom/grids/gridindex.html
http://spaceplace.jpl.nasa.gov/en/kids/math_links.pdf
http://www.teachingideas.co.uk/maths/carrolldiagrams.htm
http://www.teachingideas.co.uk/maths/introducingcarrolldiagrams.htm
http://www.mathsonline.co.uk/nonmembers/resource/index.html
http://www.crick.northants.sch.uk/Flash%20Studio/cfsmaths/cfsmaths.htm
http://www.mathsnet.net/
http://www.teachingmoney.co.uk/ws/moneygridUK.html
http://www.teachingtables.co.uk/wsmiss/miss1.html
http://www.ictadvice.org.uk/index.php?section=tl&catcode=as_cu_pr_sub_08
http://www.teachingtables.co.uk/wsegg2/multigrid2.html
http://www.shambles.net/pages/learning/MathsP/Number/
http://www.nzmaths.co.nz/
http://www.oswego.org/staff/cchamber/techno/games.htm
http://www.kirklees-ednet.org.uk/subjects/maths/resources/download/
http://www.primaryresources.co.uk/maths/mathsD1.htm
http://www.standards.dfes.gov.uk/numeracy/publications/ict_resources/12874/
www.bigbrainz.com
http://math.rice.edu/~lanius/Lessons/

http://illuminations.nctm.org/Lessons.aspx (Excellent website)

http://www.aaamath.com/

http://www.funbrain.com/math/index.html

http://www.math-kitecture.com/floor.htm

http://www.planemath.com/activities/pmactivities4.html

http://school.discovery.com/lessonplans/programs/everydaymath/

http://school.discovery.com/lessonplans/programs/mathinvestigations1/

http://www.bbc.co.uk/schools/ks2bitesize/index.shtml (Great section on
handling data)

http://www.exploratorium.edu/baseball/

http://lakeharbormiddle.stpsb.org/BurasSportsMath.htm#

http://www.pbs.org/teachers/mathline/concepts/earthday/activity1.shtm

http://www.pbs.org/teachers/mathline/concepts/plants/activity3.shtm
(Figure out the surface area of leaf)