// OPTIVER · MENTAL MATH
Optiver 80-in-8: Rules, Timing and Penalties
The 80-in-8 is the first filter in Optiver's reported screening battery: eighty arithmetic items, eight minutes, no calculator. The arithmetic is easy. The clock and the penalty for a wrong answer are what make it hard.
The format at a glance
| Items | 80 |
|---|---|
| Time | 8 minutes: about 6 seconds an item |
| Content | Integers, fractions, decimals and percentages, mixed |
| Marking | +1 correct, -1 wrong, 0 skipped (candidate-reported) |
| Pass mark | About 56 reported; 70+ is competitive |
| Navigation | No going back: answer or skip, and the next item loads |
| Tools | No calculator; scratch paper only |
Train under the exact 80-in-8 rules
Run the full Optiver-style sitting with the 80-in-8 clock and negative marking, or warm up on the free drill first.
How the scoring changes your strategy
With -1 for a wrong answer, a blind guess on a four-option item has negative expected value, and on a free-entry item it is worse. A skip costs nothing but the second you spent looking. So the real skill is triage: recognise within a second or two whether an item has a fast route, and skip it if not.
Six seconds an item means you cannot afford long multiplication. You need the shortcuts on reflex: difference of squares for numbers straddling a round number, swapping percentages (15% of 240 is 240% of 15), and scaling decimals out before you divide.
Question mechanics
- Addition and subtraction of two- and three-digit numbers, often with negatives.
- Multiplication designed so a shortcut beats long multiplication (47 × 53, 25 × 36).
- Division with decimals: 3.6 ÷ 0.12 is 360 ÷ 12.
- Fractions and percentages: which is larger, 7/15 or 4/9; 12.5% of 64.
What 56 out of 80 actually requires
If you answer 64 items and get 60 right, you score 60 - 4 = 56. That is 64 attempts in 480 seconds, 7.5 seconds each, at 94% accuracy. Every wrong answer costs you two items' worth of margin: the point you did not get and the point you lost.
Frequently asked questions
How many questions are on the Optiver 80-in-8?
Eighty arithmetic items in eight minutes, about six seconds each, as candidates report it.
Does the Optiver 80-in-8 have negative marking?
Candidates report +1 for a correct answer, -1 for a wrong one and 0 for a skip, so guessing blind loses points on average.
What is a good score on the 80-in-8?
About 56 is the reported pass mark and 70 or more is competitive.
Related
Outcry is not affiliated with, endorsed by or sponsored by any firm named on this page. Formats are candidate-reported unless stated otherwise, and firms change them between cycles.