|HOW TO USE A CONCENTRATION
Always use a metronome set at a comfortable, but challenging speed. For the first run-through simply recite each number with a variable set for the entire chart. (i.e. subtract "2" from each number - the first line reading " 11 23 40 15
6 28 " and so on.) Once that can be done smoothly at a respectable tempo, move the gradient of difficulty up a notch or two. Read the chart in reverse (beginning at the bottom right) and/or make each cell alternate between "+2" and "-2", or any number you wish. (in this case, the first line reading " 15 23 44 15 10
28 "). Then try reciting a color (instead of the number) on all squares bearing the number "5". After this, difficulty can be raised yet again by overlapping a condition to, for instance, only the ODD numbers. (a condition being perhaps a finger snap or a clap on the odd number only) Now that you have an understanding of how this works, you can tailor charts like this to your own needs.