Use systems
From the time I was ten years old, 12 x 49 was always (12 x 50) - 12. It's easier to figure in your head this way (588, by the way). I didn't get any credit for my personal algorithms then, but they are selling these shortcuts on late-night TV now, because they work. You can find your own easier ways to do mental math or other mental tasks, or read a good book on them.