We can think of a pattern as a design or picture which repeats itself at regular intervals.

The simplest pattern is the set {0, 1, 2, 3, 4, ....} where one is added each time.
0, (0+1=1), (1+1=2), (2+1=3), ....

To solve number patterns, examine the differences between numbers and try to find a pattern.
 

Now look at the numbers in the red blocks below {2,12,22,32,42,52,62,72,82,92} .
Notice ten is added to each number forming the pattern. In fact this pattern applies to all the  vertical (up/down) lines.

The numbers in the blue blocks running at an angle {4,15,26,37,.....} increase by eleven each time. What about the pattern for the numbers in the yellow blocks ?
 

Observe The
Patterns