i used to hate the times table but i definitely think it's essential to mental math. even if you vaguely remember it it will help. like knowing 42 shows up somewhere in the 7x and 6x may help you remember 6x7. or if you remember a neighbor you can just add or subtract the number once. for example if you don't remember 7x6 it definitely helps to know each neighbor (both of which are easier to me since one is a 5x and one is a square number)... so either you think about 7x5 which is 35 so you can add another 7 to it or 6x6 which is 36 so you can add another 6 to it.