Math and Math-Related Applications

Geometry Manipulatives
Tessellation VI (freeware) - grades 2-12: http://tesselation.sourceforge.net
Tan Free V2.1.1 (freeware) - grades 1-12: http://www.freewarepalm.com/games/smallwaretangramsfree.shtml

Place Value/Number Systems
Palm Abacus V0.961 (freeware) - grades 3-12: http://www.palmgear.com/index.cfm?fuseaction=software.showsoftware&SID=2E83425C-CF18-AC90-80A7272D7DEFDC85&PartnerREF=&prodID=54506
Numerus V1.4 (freeware) - grades 3-12: http://www.palmblvd.com/software/pc/Numerus-2001-10-11-palm-pc.html

Mental Math
Algebraf V1.0 (freeware) - grades 4-12: http://www.freewarepalm.com/games/algebraf.shtml
Mental Arithmetic V1.2.1 (shareware; $25) - grades 4-12: http://www.bubbling.com
BeSmart V1.4 (shareware; $8) - grades 4-12: http://www.palmgear.com/index.cfm?fuseaction=software.showsoftware&prodid=6950
Monkey Math V0.5 (freeware) - grades K-2: http://www.pilotzone.com/palm/preview/160071.html

Economics
InflationMaster V2.7 (freeware) - grades 2-12: http://www.freewarepalm.com/calculator/inflationmaster.shtml
powerOne Personal V3 (shareware; $9.99) - grades 7-12: http://www.infinitysw.com/products/poweronepersonal.html

Science
Ecological Footprint Calculator V3 (freeware) - grades 4-12: http://www.kidsolve.com/products/palm/efc/

Career Exploration
Salary Utility V2.6 (freeware) - grades 6-12: http://www.freewarepalm.com/calculator/salaryutil.shtml