Ask HN: Challenging math software for 8yo kid?

She greatly enjoys mental arithmetic and I'd like to find some software that challenges her. There's loads of stuff out there but I don't know whether any of it is good. Ideally looking for personal recommendations.

For context, the mental arithmetic she does is stuff like adding 3 digit numbers, multiplying 2 digit numbers and some basic algebra. She continually asks me for math problems but I'm not sure where to go next.

Thanks in advance.

I'm making the assumption that she gets her regular mathematics lessons in school, and that is why you are asking about software rather than books. (Please correct me if that assumption is not correct.) A good set of books can be challenging and fun even if it is not on a computer. I like Miquon Math

http://www.keypress.com/x6252.xml

for starting out my children, and then the Singapore Primary Mathematics materials (which now have an edition aligned to United States curriculums standards)

http://www.singaporemath.com/Primary_Mathematics_Stds_Ed_s/1...

appropriately supplemented by ALEKS

http://www.aleks.com

and EPGY.

http://epgy.stanford.edu/district/info.html

(The last two of these resources are online services with adaptive learning software.)