If you don't know the multiplication table by heart,
then carry it with you and refer to it as needed.
user: w3reader pw: Tiz4good sunago.daviesb @ gmail.com (c) Barry Davies 2013 

Calculators have made the times table obsolete? We don't need our legs because we have cars. 4function, scientific, and financial calculators are very useful. However, they force every square root and fraction into the roundedness of the decimal, and this obstructs our understanding of numbers. The human brain is the more powerful tool. 

digits upright, and count the digits left to right: one to ten. Lower the 7th digit, and read the upright digits as a number: 9 x 7 = 63 You have just learned the 9 times table.¹ 

of the past twenty years may have been simply to take the time to understand. It's time the main stream does not allow us to have, and I got it by leaving said flow. The subject matters were classical tensor analysis and the real number system. It seems to me that this missing time, along with the lack of resolution of other issues, suffices to explain why so many people have so much trouble with mathematics. I propose to the great and grand parents that we take the time and then exert our influence in the stream. 
¹ I learned this from a friend who attributed it to Jaime Escalante and the movie "Stand and Deliver"  google for more.