Levelling Up Your Memory With brain training
   If you’re intent on ‘levelling up’ your memory, then you have the option to do that through a number of techniques.
One option is to use some form of brain training. And here there is one strategy that stands out above the rest…
‘Dual N-Back’ training is an exercise that involves watching sequences of letters or numbers and then identifying when there is a repetition. The ‘N’ here represents how many steps back you are looking and of course it becomes harder the more information you need to retain.
      The ‘dual’ aspect means you are actually watching for repetitions in two separate streams of stimuli
This is the only form of structured brain training that has been repeatedly supported by the research as a means to increase not only working memory but also fluid intelligence and attention (1, 2).
But here’s where you need to start being a little discerning. The usefulness of improving your working memory is questionable and the amount of work you’d need to do to see results is significant.

Working memory is the type of memory we use while carrying numbers during mental arithmetic and it’s how we remember phone numbers briefly while looking for a pen. The span of working memory is believed to be 7 +/- 2 meaning it can go up to 9 and as low as 5