extend numerical patterns;

http://www.beaconlearningcenter.com/WebLessons/BrendasBedroom/default.htm

http://www.oswego.org/ocsd-web/games/spookyseq/spookysqno.html

http://www.oswego.org/ocsd-web/games/spookyseq/spookytrino.html

http://www.learnalberta.ca/Launch.aspx?content=%2fcontent%2fmesg%2fhtml%2fmath6web%2fmath6shell.html

http://www.bbc.co.uk/schools/revisewise/maths/number/10_act.shtml