I collected data for one month on the timestables.me.uk website from the Online Times Tables Test to look at which questions were most commonly answered correctly or incorrectly.
During the month chosen, there were 1.2 million times tables questions answered by schoolchildren from around the world of which 91.4% were answered correctly.
Looking in more depth at the number of questions answered correctly led to the following table of results.
The number 2-12 in the vertical column is the first multiplicand, and the number 2-12 in the horizontal header row is the second multiplicand. For example, the answering success rate for 7 times by 11 is found to be 95.9%.
The ten questions most often answered correctly have a black border around their success rate, and the ten questions most often answered incorrectly have a white border around their success rate (and white font).
Looking at the ‘easiest’ and most ‘difficult’ times tables questions as judged by the success with which they were answered, the 10 and 11 times tables are the easiest except for the 11×11, 12×11, and 11×12 which are the most difficult to remember times tables multiplication facts of all.