How the Harver Numerical Reasoning test works
Each item shows a sequence ending in a question mark, with answer options beneath. Unlike many numerical tests there are no tables, charts or word problems: the whole subtest is number sequences, and Harver describes it as discovering and recognising systems in them.
Harver links it to jobs that need numerical insight and analytical problem-solving. Like the other subtests it is timed, scored on correct answers and reported against a norm group.
How to find the rule in a number sequence
Try these checks in order until one fits every step:
- Write down the differences between neighbouring numbers. A constant difference is a fixed step.
- If the differences change, look at the differences of the differences, or check whether they double.
- If the numbers grow fast, try multiplying: divide each number by the one before it.
- If the sequence zigzags, split it into odd and even positions. Two simple series may be woven together.
- Check your rule on every step, not just the last two, before you pick an answer.
Worked examples
4, 7, 13, 25, 49, ? with the options 73, 89, 96, 97 and 98. The differences are 3, 6, 12 and 24, doubling each time, so the next difference is 48 and the answer is 49 + 48 = 97. The same rule in another form: double the number and subtract 1.
2, 9, 4, 11, 6, 13, ? The numbers jump up and down, so split them. Positions 1, 3 and 5 read 2, 4, 6; positions 2, 4 and 6 read 9, 11, 13. The missing number is the seventh, so it belongs to the first series, and the answer is 8.
Tips for the real Numerical Reasoning test
- Keep pen and paper to hand for writing differences. Working them out in your head invites slips.
- Use the options. If your rule gives a number that is not among them, recheck the rule.
- Brush up on doubling, halving, square numbers and times tables. Fast recall speeds up every rule check.
- If an item resists two or three rule checks, give your best answer and move on.
Practise Harver Numerical Reasoning on CogniPrep
Our version has 30 sequences in 15 minutes, five options each, running from fixed steps to alternating operations. Select an answer and press Next; there is no Skip and no going back. Your score is the number right out of 30. Harver does not publish its count or clock, so these are ours.