Figure series, mirrors, embedded shapes and paper folding.
About Pattern Completion
A pattern completion question shows squares and circles arranged so that the symbols repeat at a fixed interval along every row and down every column, with one small block of the pattern missing. The block is found by carrying on that repetition, so the answer is decided by the cells immediately around the gap.
What you need to understand
The symbols repeat at a fixed interval along each row, and at a fixed interval down each column.
The repeat may be as short as two, giving an alternating pattern, or as long as three.
A cell is decided by the cells that share its place in the repeat, not only by its neighbours.
The row above the gap, the row below it and the columns on either side all constrain the missing block.
Every cell outside the gap is consistent with the same repeat, which is what makes the answer unique.
A block that continues the repeating order is correct; a block copied from a neighbouring position is the commonest wrong answer.
Because the gap is usually two cells by two cells, all four missing symbols have to be right, not just one.
How to work through these questions
Find the repeat along the rows first: compare the symbol in one cell with the cells a fixed distance to its right until the symbol recurs.
Do the same down the columns to find the vertical repeat.
Read the cells directly above and directly below the gap, and the cells to its left and right.
Continue the repeat through the gap, one cell at a time, rather than reading the neighbouring block across.
Write the four symbols of the missing block down before looking at the options.
Compare each option against that block, symbol by symbol, and discard any that differs in even one cell.
Check the answer back against the pattern by imagining it in place and confirming the repeat is unbroken.
Mistakes that cost marks
Using the row alone and ignoring the column, when both constrain the block.
Assuming the symbols simply alternate when the repeat is in fact three long.
Copying the block from immediately to the left of the gap, which is plausible but repeats a part of the pattern rather than continuing it.
Lining the block up one cell out, so that the right symbols appear in the wrong places.
Checking one cell of the four and taking the first option that fits it.
Reading the pattern down the columns when it repeats along the rows, which gives a block that is transposed.
Worked example
A grid is filled with squares and circles alternating like a draughtboard, and a block of two cells by two cells is shaded out in the middle. Which block completes the pattern?
Read along the row above the gap. The symbols alternate square, circle, square, circle.
The gap covers two cells of that column range, so continue the alternation into the first missing row: the two cells take the opposite symbols to the cells directly above them.
Now read along the second missing row. It also alternates, and it starts with the opposite symbol to the row above, which is what a draughtboard does.
Write the four symbols down: the first row of the block takes what the alternation requires, and the second row the opposite of the first.
Compare with the options. The block that matches in all four cells is the answer, and a block with two symbols swapped fails at the second row.
Answer: The block that continues the alternation in both rows, with the second row the opposite of the first.
Practice questions with answers
A few Pattern Completion questions with the full solution shown, so you can see
how the method is applied before you attempt the timed set.
Question 1
The pattern below repeats squares and circles in a fixed order. A block of 2 by 2 cells is missing from the shaded area.
Which block completes the pattern?
A
B
C
D
Answer: Option C — with explanation
Read along any row of the pattern and the symbols repeat at a fixed interval, so the missing block is decided by the cells immediately around it.
Only one of the four blocks fits the pattern without interrupting it.
Common mistakes
- read the pattern the other way round, as circles where it has squares
- took the block from the far corner of the pattern
- copied the block from one row lower than the gap
Question 2
The pattern below repeats squares and circles in a fixed order. A block of 2 by 2 cells is missing from the shaded area.
Which block completes the pattern?
A
B
C
D
Answer: Option B — with explanation
Read along any row of the pattern and the symbols repeat at a fixed interval, so the missing block is decided by the cells immediately around it.
Only one of the four blocks fits the pattern without interrupting it.
Common mistakes
- copied the block from one row lower than the gap
- read the pattern the other way round, as circles where it has squares
- copied the block from one column further along
Question 3
The pattern below repeats squares and circles in a fixed order. A block of 2 by 2 cells is missing from the shaded area.
Which block completes the pattern?
A
B
C
D
Answer: Option C — with explanation
Read along any row of the pattern and the symbols repeat at a fixed interval, so the missing block is decided by the cells immediately around it.
Only one of the four blocks fits the pattern without interrupting it.
Common mistakes
- copied the block from one row lower than the gap
- copied the block from one column further along
- swapped the squares and circles over
Question 4
The pattern below repeats squares and circles in a fixed order. A block of 2 by 2 cells is missing from the shaded area.
Which block completes the pattern?
A
B
C
D
Answer: Option B — with explanation
Read along any row of the pattern and the symbols repeat at a fixed interval, so the missing block is decided by the cells immediately around it.
Only one of the four blocks fits the pattern without interrupting it.
Common mistakes
- copied the block from one column further along
- read the pattern the other way round, as circles where it has squares
- copied the block from one row lower than the gap
Question 5
The pattern below repeats squares and circles in a fixed order. A block of 2 by 2 cells is missing from the shaded area.
Which block completes the pattern?
A
B
C
D
Answer: Option B — with explanation
Read along any row of the pattern and the symbols repeat at a fixed interval, so the missing block is decided by the cells immediately around it.
Only one of the four blocks fits the pattern without interrupting it.
Common mistakes
- copied the block from one row lower than the gap
- read the pattern the other way round, as circles where it has squares
- copied the block from one column further along
Frequently asked questions
How do I find the repeat in a pattern?
Compare a cell with the cells at a fixed distance from it along the row. When the symbol recurs, that distance is the repeat. Check it against a second row before relying on it.
Do I need the rows or the columns?
Both. Each constrains the missing block, and where one alone would allow two possibilities, the other settles it.
Why is the block next to the gap the wrong answer?
Because the pattern continues along the row; it does not repeat the neighbouring block. A neighbouring block has its own place in the repeat, and copying it puts the symbols one step out.
What if the pattern repeats every three cells?
Then look three cells away rather than two. Counting the symbols in a complete row is the quickest way to see whether the repeat is two or three long.
Does the size of the gap matter?
It fixes how many symbols have to be right. A two by two gap needs four correct symbols, so an option that is right in three cells and wrong in the fourth is still wrong.
Take the Pattern Completion test
Two timed papers on the same syllabus — sit the foundation paper first,
then the advanced one. Both use the real exam paper format with a full
step-by-step review of every question once you submit.
