Fun for kids, but the vast majority of questions are 1s, 2s, 5s, and 10s -- the easy ones, in other words. Should spend more time on 6s, 7s, 8s, and 9s. It also doesn't seem to learn that you already know the simple ones, and keeps asking over and over what 1x4 or 10x8 is. If you get a question wrong, it will ask you again until you learn it, but it doesn't seem to adapt at all to what you actually get right. Frustrating.