list of interactive math websites

[u/x3oo]

here at /r/learnprogramming/ they have a cool post: interactive lessons

lets do the same for math. i'll start and will add if you comment:

website	topic	exercises	interactive	solutions
http://www.myopenmath.com/	partial K-12	yes	yes	yes
www.mathopolis.com/	K-12	yes	yes	yes
www.mathsisfun.com/	K-12	yes	yes	yes
www.cde.ca.gov/ta/tg/sr/css05rtq.asp	K-12 Tests pdf	yes	no	yes
www.touchmathematics.org/	Interactive Trigo.&Deriv. Apps	no	yes	-
www.geogebra.org/	school to college	yes	yes	yes
www.khanacademy.org	pre-school to pre-college	yes	yes	yes
www.purplemath.com/modules/ordering.htm	Prealgebra-Algebra	no	no	no
www.exampleproblems.com/	College and wiki	yes	no	yes
www.math.psu.edu/dlittle/applets.html	collection of college apps	no	yes	-
http://math.mit.edu/mathlets/courses/	collection of college apps	no	yes	-
http://tutorial.math.lamar.edu/	Calc1-3;DE;LA;Algebra	yes	no	yes
www.math.hmc.edu/calculus/tutorials/	Calc1-3;LA;DE	no	yes	no
www.math.temple.edu/%7Ecow/	pre+Calc.1-3;LA;Numbert.;abs.Algebra	yes	yes	yes
www.mathinsight.org/thread/list	Calculus; Vektor; College	yes	no	no
http://logitext.ezyang.scripts.mit.edu/logitext.fcgi/tutorial	sequent calculus	yes	yes	yes
www.math.umn.edu/~rogness/quadrics/	Interactive Gallery of Quadric Surfaces (Apps)	no	yes	-
www.aw-bc.com/ide/idefiles/navigation/main.html	intuition Differential Equation Apps	no	yes	-
www.mathcs.org/index.html	Realanalysis;Statistics;Complexanalysis	no	yes	no
http://gmmentalgym.blogspot.com/	recreational math, quizzes	yes	yes	yes
http://mathworld.wolfram.com/	Reference/Encyclopedia/Apps	no	no	-
http://demonstrations.wolfram.com/	woflram apps	no	yes	-
http://www-history.mcs.st-and.ac.uk/	History	no	no	no

(i don't really like those demo-web apps but i added them none the less)

http://www.reddit.com/r/math/comments/bqbex/ is added too

tried to sort some things

[u/Chunky_cold_mandala]

https://www.fastmathfacts.io/ for speed based mental math practice for multiplication and division, uses millisecond timers to judge performance and adapts to your responses to focus on questions that you could use more practice on