What is the 80 in 8 test?
The 80 in 8 test is the first screening stage of Optiver’s hiring process for trading, quant and tech roles. As the name suggests, it asks you to answer 80 mental arithmetic questions in 8 minutes — an average of just six seconds per question. The test is taken online, without a calculator (or pen and paper), and measures the two skills a market maker relies on most: fast mental math and accuracy under pressure.
Candidates who clear the bar move on to later rounds, which typically include a number-sequences test, interactive games, and interviews with probability questions and market-making exercises. Because Optiver receives applications from all over the world, the 80 in 8 acts as an efficient first filter — and because the format is unusual, almost everyone benefits from practicing it beforehand.
Format and rules
- 80 questions in 8 minutes, shown one at a time — about six seconds each
- Multiple choice with four options; you pick one and the next question appears immediately
- You cannot skip ahead or return to previous questions
- No calculator; pen and paper are offered but slow you down — the test is designed to be done in your head
- Options are deliberately deceptive: the correct value may appear in unreduced form (an answer of 6 shown as 72/12), and distractors sit one digit away
- Heads-up on notation: Optiver is Dutch, and the real test may use commas as decimal separators (0,078) and occasionally colons for division
80 in 8 question types
The test stays close to school arithmetic — four operations on integers, fractions and decimals — and first-hand accounts agree the numbers are smaller than you expect. What makes it brutal is the pace and the traps in the answer choices. These are the families you will face:
The missing-operand shape (the signature trap)
Many questions give you the result and ask for a missing operand: 66 × ? = 138.6, 2/3 − ? = 1/6, 0.078 ÷ ? = 13. Each is an inverse operation in disguise — 66 × ? = 138.6 is really 138.6 ÷ 66. Practice reframing these instantly; that reframing, not raw computation, is the single biggest score lever on this test.
Arithmetic on integers and decimals
Two-digit addition and subtraction (54 − 29), division from the times tables (84 ÷ 6), and multiplication that tops out around 15 × 15 — knowing through 19 × 19 covers you with room to spare. Decimals run two to three places and test your decimal-point discipline: 0.05 − 0.004 = 0.046 (not 0.01), 0.6 × 0.03 = 0.018, 0.078 ÷ 0.006 = 13.
Fractions
Addition and subtraction with single-digit or small double-digit denominators (2/3 − 1/2), multiplication by whole numbers (3/8 × 240 = 90), and fraction results that may show up unreduced among the options. Fluency in fraction–decimal conversions — 1/8 = 0.125, 3/4 = 0.75, 5/8 = 0.625 — pays off everywhere.
What you will NOT see
Percentages, powers and roots are not on the current 80 in 8 — those belong to other stages of Optiver’s assessment and to other firms’ tests. Every question here is a single operation on plain numbers: no word problems, no chained calculations, and fractions and decimals never mix within one question. (Practice mode offers powers and roots as optional extras, because they are useful for trading interviews generally.)
How the 80 in 8 is scored
Scoring is net-based: +1 for a correct answer, −1 for a wrong one — and, per first-hand accounts, a blank left in the middle of the test also costs −1, so the test rewards working start-to-finish rather than hunting for easy questions. Anything left blank when time runs out simply scores 0.
Where does your net score land? The bands we rate your practice runs by:
- 75–80 Cracked
- 70–74 Excellent
- 60–69 Strong
- 50–59 Solid
- <50 Keep practising
Optiver publishes no official bar, but the consistently reported figure is a pass line around 55 net points, with 70+ considered competitive — from a reported pass rate of roughly 15%. In correct-answer terms that means about 62–68 correct with only a handful of mistakes.
The strategy that follows: never leave a mid-test question blank (a guess is break-even versus −1), but never guess wildly either — one wrong answer cancels a correct one. Treat these numbers as directional; Optiver tunes the process over time.
How to prepare: mental math tips for trading tests
The 80 in 8 is one of the most trainable hiring tests you will ever face. Unlike aptitude tests that claim to measure fixed ability, mental math speed responds quickly to deliberate practice — most candidates see meaningful improvement within two weeks of daily drills. This page is a practice tool for exactly that; here is how to use it well.
Pacing: find the six-second rhythm
Six seconds per question is a metronome, not a per-question deadline. Some answers come in two seconds (7 × 8); some legitimately take ten. What you must avoid is the twelve-second stall on a missing-operand question. Run timed mocks and watch your average seconds per question — when it creeps above eight, it is your pacing, not your math, that needs work.
Accuracy beats speed — the math of +1/−1
Under net scoring, 62 correct with 5 wrong (net 57) beats 70 attempted with 18 wrong (net 52). Chase streaks of clean answers before you chase raw attempts; speed that arrives without errors is the only kind that sticks.
Drill the three real levers
First, multiplication tables to 19 — the whole integer section is recall once you have them. Second, decimal-place discipline: drill 0.05 − 0.004 and 0.6 × 0.03 until the point placement is automatic. Third, the missing-operand reframe: whenever you see a ?, mentally convert the question into a division or subtraction before computing. The practice mode on this site drills each family in isolation, untimed, with instant feedback — ten focused minutes on your weakest lever usually moves your net score more than another full mock.
Frequently asked questions
What is the 80 in 8 test?
The 80 in 8 is Optiver’s first-round math screening test: 80 mental arithmetic questions in 8 minutes, four-option multiple choice, with no calculator. It is used for trading, quant and other front-office roles.
Is this the official Optiver test?
No. 80in8 is an independent practice tool and is not affiliated with, endorsed by, or connected to Optiver. It replicates the reported format of the 80 in 8 test — including the missing-operand questions and the unreduced answer options — so you can practice under realistic conditions.
How many questions are on the test, and how long do I have?
80 questions in 8 minutes — about six seconds each. This site defaults to the same format, and also lets you customize the length and time limit for shorter drills.
What score do I need to pass the 80 in 8?
Scoring is +1 per correct answer and −1 per wrong one. Optiver publishes no official bar; candidate reports consistently put the pass line around 55 net points, with 70+ considered competitive.
Are wrong answers penalized?
Yes — each wrong answer costs a point, and first-hand accounts report that a blank left in the middle of the test also costs a point, so answer every question rather than jumping around. Trailing blanks when time runs out score zero.
What question types appear on the 80 in 8?
The four operations on integers, fractions and decimals — including small-decimal questions like 0.078 ÷ 0.006 — plus the signature missing-operand format (66 × ? = 138.6). Percentages, powers and roots are not on the current test.
Can I use a calculator or paper?
No calculator. Pen and paper are offered at the real test, but at six seconds a question there is no time to write — train to do everything in your head.
Does this practice test work on my phone? Do you store my data?
Yes — the site works on any modern browser, phone included, and even offline once loaded. All your scores and history are stored only on your own device; nothing is uploaded. Anonymous usage statistics are collected with Google Analytics.