Missing Letters Puzzles

About Missing Letters Puzzles

A missing letter puzzle shows a grid of letters with one replaced by a question mark. The letters move on by a fixed number of places along each row and by a fixed number down each column, and finding those two steps is the whole task, because once they are known the missing letter follows from any other letter in the grid.

What you need to understand

Along a row the letters move on by the same number of places each time.

Down a column the same is true, with its own step.

The two steps are usually different, and neither has to be one.

A step can be checked on any row or column, so use the pair of neighbouring letters that is easiest to count between.

From a known letter, count the row steps across and the column steps down to reach the missing cell.

Count through the alphabet one letter at a time. A step of three means three places on, not four.

How to work through these questions

Pick a row with no question mark and count how many places separate neighbouring letters.

Do the same for a column free of question marks, which gives the second step.

Check both steps against another row and another column before trusting them.

Find any letter that shares a row or a column with the question mark.

Move from that letter to the question mark using the steps, counting one place at a time.

Read the resulting letter back against the grid to confirm that it fits.

Mistakes that cost marks

Counting the letters between two letters instead of the places moved, which puts the answer one out.
Using the row step down a column, or the column step along a row.
Assuming the row step and the column step are the same.
Losing count part way through the alphabet.
Starting from the wrong known letter and arriving at a letter that does not fit the rest of the grid.
Forgetting that the step is the same for every row, not only for the one examined.

Worked example

In a grid the letters follow a pattern along the rows and down the columns. One row reads A, C, E and the row beneath it reads C, E, G. Which letter belongs where the question mark sits in the second row?

Along the first row the letters go A, C, E, so the row step is 2.
Down the first column the letters go A then C, so the column step is also 2.
The question mark is in the second row and the third column.
Starting from A at the top left, move two places down and four places across: A moved on by 2 + 4 is G.
Checking the second row, C, E, G, the row step of 2 holds, so G fits.

Answer: G

Practice questions with answers

A few Missing Letters Puzzles questions with the full solution shown, so you can see how the method is applied before you attempt the timed set.

Question 1

In this grid the letters follow a pattern along the rows and down the columns.

Which letter should replace the question mark?

Answer: Option D — with explanation

Read across a row and the letters move on by 2 places each time, and read down a column and they move on by 2. From the first letter of the grid that puts E at the question mark. Common mistakes - stepped along the grid by the wrong amount: G - stepped along the grid by the wrong amount: C - stepped along the grid by the wrong amount: I

Question 2

Each row and each column of this grid moves through the alphabet in a fixed way.

Which letter should replace the question mark?

Answer: Option B — with explanation

Read across a row and the letters move on by 1 place each time, and read down a column and they move on by 4. From the first letter of the grid that puts L at the question mark. Common mistakes - stepped along the grid by the wrong amount: I - stepped along the grid by the wrong amount: H - stepped along the grid by the wrong amount: F

Question 3

Work out how the letters change along the rows, and then how they change down the columns.

Which letter should replace the question mark?

Answer: Option C — with explanation

Read across a row and the letters move on by 2 places each time, and read down a column and they move on by 4. From the first letter of the grid that puts F at the question mark. Common mistakes - stepped along the grid by the wrong amount: E - stepped along the grid by the wrong amount: D - stepped along the grid by the wrong amount: C

Question 4

One letter of this grid has been replaced by a question mark.

Which letter should replace the question mark?

Answer: Option B — with explanation

Read across a row and the letters move on by 2 places each time, and read down a column and they move on by 4. From the first letter of the grid that puts L at the question mark. Common mistakes - stepped along the grid by the wrong amount: J - stepped along the grid by the wrong amount: I - stepped along the grid by the wrong amount: K

Question 5

In this grid the letters follow a pattern along the rows and down the columns.

Which letter should replace the question mark?

Answer: Option A — with explanation

Read across a row and the letters move on by 3 places each time, and read down a column and they move on by 4. From the first letter of the grid that puts I at the question mark. Common mistakes - stepped along the grid by the wrong amount: G - stepped along the grid by the wrong amount: F - stepped along the grid by the wrong amount: E

Frequently asked questions

How do I find the step along a row?

Count how many places separate two neighbouring letters. From A to C is two places, because B lies between them.

Can the row step and the column step be different?

Yes, and they usually are. Work each one out separately, from a row and a column that contain no question marks.

What if the grid has more than one question mark?

Work from the letters that are present. As long as one letter is known in the right row or column, the steps carry you to the missing cell.

How do I avoid counting errors?

Count one place at a time and say the letters as you go rather than subtracting. Sliding a finger along the alphabet is more reliable than arithmetic here.

Does the pattern ever run backwards?

It can, but these grids move forwards. If a backwards step is the only one that fits, recount the forwards step before accepting it.