I don't remember exactly when he started, but I know we were doing memory training when he was 6. The first thing we did was him repeating back a numerical sequence he heard from me.
I started doing comparable games (repeat long words, non-sense words and sentences) when they were quite young (basically growing out of talking with them when they started learning to talk). With the older trying too. But these games only confirm the same thing: Repeating a sequence by rote is hard (for them). Repeating whole sentences is much easier - but it likely happens that only the meaning is transported not the literal form. Songs are even more easy - but I'd guess that that's due to other types of memory (rhythm?) cueing in.
I continually train my ten-year-old son’s working memory, and urge parents of other young children to do likewise. While I have succeeded in at least temporarily improving his working memory, I accept that this change might not be permanent and could end a few months after he stops training. But I also believe that while his working memory is boosted so too is his learning capacity.
I have a horrible working memory that greatly hindered my academic achievement. I was so bad at spelling that they stopped counting it against me in school. In technical classes I had trouble remembering what variables stood for. My son, in contrast, has a fantastic memory. He twice won his school’s spelling bee, and just recently I wrote twenty symbols (letters, numbers, and shapes) in rows of five. After a few minutes he memorized the symbols and then (without looking) repeated them forward, backwards, forwards, and then by columns.
My son and I have been learning different programming languages through Codecademy. While I struggle to remember the required syntax of different languages, he quickly gets this and can focus on higher level understanding. When we do math learning together his strong working memory also lets him concentrate on higher order issues then remembering the details of the problem and the relevant formulas.
You can easily train a child’s working memory. It requires just a few minutes of time a day, can be very low tech or done on a computer, can be optimized for your child to get him in flow, and easily lends itself to a reward system. Here is some of the training we have done:
The key is to keep changing how you train your kid so you have more hope of improving general working memory rather than the very specific task you are doing. So, for example, if you say a sequence and have your kid repeat it back to you, vary the speed at which you talk on different days and don’t just use one class of symbols in your exercises.