My mental method is not quite FOIL, for what it's worth. I distribute over one of the numbers -- so 47 * 68 = 47 * 60 + 47 * 8, and then compute the compute tho

My mental method is not quite FOIL, for what it's worth. I distribute over one of the numbers -- so 47 * 68 = 47 * 60 + 47 * 8, and then compute the compute those (2400 + 420 = 2820). Then I grab additional terms: 2820 + 40 * 8 = 3140. 3140 + 7 * 8 = 3196 Among other things this scales better to larger numbers. I use it because it's more 'linear' -- I only need to remember one accumulated number at a time.