Missing letters puzzles - Section 1

Working through the diagram in columns, from top to bottom, letters move through the alphabet in steps of 5 for the left hand column, 7 for the next one, then 9, then 11.

Starting with the letters in segments of the top left circle, add 3 to the numerical values of the letters, and write the results in the top right circle, with the relative positions of the letters moving 1/4 turn clockwise. Repeat this pattern, adding 4 to the values of the letters for the lower right hand circle, and adding 5 for the letters in the lower left hand circle, putting the results in the segments 1/4 turn clockwise each time.

The sum of the numerical values of the letters in each column of the diagram equals 29.

Start at the top left and move to the right, then down one row and to the left etc in a snakes and ladders pattern. Letters advance through the alphabet 9 letters at a time.

Working from top to bottom, letters move through the alphabet in steps of 2, then 3, then 2 etc.

Start on the top left of the diagram and work from top to bottom in columns, from left to right. Letters are written in alphabetic order, in a repeated sequence of steps of 5, 6 and 7.

Start at the top left of the diagram, and work down the left hand column, then along one space to the right and up the next column, in a snakes and ladders pattern, write the following repeated sequence of letters: A C P R F D U.

Join pairs of letters at opposite sides of the diagram, with lines which run through the centre. The sum of the numerical values of the pairs of letters is always 25.

Start at the top of the diagram and work in rows, from left to right, top to bottom. Letters move through the alphabet in steps of 4, 5, 6, 7, 8, 9 and 10, before repeating this sequence.

Adding 1 to the numerical values of each letter gives the sequence of Prime Numbers.