Here is a sequence of patterns made from square tiles.
Pattern 1: 6 tiles (a central row of 4 and 1 tile above and 1 tile below the center). Pattern 2: 11 tiles (a central row of 7 and 2 tiles above and 2 tiles below the center). Pattern 3: 16 tiles (a central row of 10 and 3 tiles above and 3 tiles below the center).
In the space below, draw pattern number 4.
Work out the total number of tiles to make pattern number 15.
