How cijferpatronen works
Cijferpatronen is the part of the police cognitietest built on numbers. The police describe the whole test as measuring numerical insight and general reasoning. The questions are reported to be partly plain number series and partly more complex number patterns. How you enter the answer is not published by the police.
Like the other parts, it adapts to you. It opens with a relatively easy question, gets harder after right answers and easier after wrong ones, and scores you on the difficulty you reach. Hard questions get minutes rather than seconds, and the bar in the top right appears only when ten seconds are left.
Only pen and paper are allowed. A calculator is not, so every step has to be done in your head or on scrap paper.
How to solve a number pattern
Test the common rules in order:
- Write the difference between each pair of neighbours. A steady difference solves it.
- If the differences change, write the differences of the differences. A steady second step often appears.
- Try ratios: is each number double, triple or half the one before?
- Try two operations together, such as times two then plus one.
- Read every other number. Two series may run side by side.
Worked examples
Series: 4, 9, 19, 39, ?. The differences are 5, 10, 20, so they double, and the next difference is 40: the answer is 79. The same rule seen another way: each number is twice the one before plus one (39 × 2 + 1 = 79).
Series: 2, 30, 5, 27, 8, 24, ?. Every other number: 2, 5, 8 climbs by 3, and 30, 27, 24 falls by 3. The missing number continues the first series: 11.
Tips for cijferpatronen
- Brush up on times tables up to 12 and on squares and doubles, since there is no calculator.
- Do not rush a hard question. The police advise against answering too quickly, and a hard item gives you minutes.
- Write the differences under the series on your scrap paper rather than holding them in your head.
- If you are stuck as the bar appears, type your best guess. A blank is wrong anyway.
- A weaker score here can be made up by the other two parts, but the police warn that an extremely low score on one part is hard to compensate.
Practise cijferpatronen on CogniPrep
Our Cijferpatronen runs 12 to 18 adaptive questions, starting easy, in three layouts: number rows, pairs of numbers in tiles and small tables. You type the missing number, with no options and no calculator. Time limits of 25 seconds, 1 minute or 2 minutes by difficulty are our estimate, hidden until the last ten seconds. At the end you get a score out of 100, weighted mostly on the difficulty you reached, and a percentile against other CogniPrep players.