If you are in possession of a BlackBerry 10 device and also a child you may like to get the two together and teach some mathematics. I discovered a range of free applications from TSL Education Ltd in BlackBerry World and after giving one a test run they are actually pretty cool and will certainly make learning a bit more fun for you child.
The target ages range from 4-7 and 7-12 years, depending on the application. In the above video I had a go of Getting Started Addition but you can then progress onto the expert edition - all for free.
Each application contains a small selection of games that require the child to correctly guess the answer to the sum asked. Some games will have the answer displayed, like in the jelly fish section of the video, and some will not - meaning the child has to work out the answer in their head without on-screen options to choose from.
Of course you don't actually have to own a child to play, but for us adults it isn't going to be very challenging or a bunch of laughs.