Mental Math Practice Formats and Calculation Techniques for Trading Tests
Summary
The document collects suggested online practice resources for candidates preparing for fast mental arithmetic tests used in trading recruitment. Respondents favor simulators that resemble the reported format, including timed sets, many questions, penalties for wrong answers, multiple choice, and practice with decimals or fractions. Other suggestions include arithmetic drills, sequence questions, and spoken prompts. The recommendations reflect individual experiences and the availability of particular websites at the time; they do not establish a definitive or universally representative version of any employer’s test.
One response also shares calculation approaches: regroup awkward additions and subtractions around round numbers, split multiplication into place-value components, simplify division by five through scaling, and square two-digit numbers by choosing a nearby round value. For square roots, it recommends bracketing the answer between familiar perfect squares and estimating between them. These methods can support speed practice, but the document gives no comparative evidence that one resource or technique improves test performance more than another.
Key ideas
- Timed practice can mimic the pace and format candidates report encountering in trading recruitment tests.
- Useful simulator features mentioned include negative marking and practice with decimals and fractions.
- Regrouping around round numbers can simplify mental addition and subtraction.
- Place-value decomposition helps break multiplication into manageable calculations.
- Perfect squares provide nearby bounds for estimating square roots.
Tags
Full text
# Alternative to tradertest.org for mental math practice # Alternative to tradertest.org for mental math practice The most recommended resource for preparation for Optiver's math test is tradertest.org. But the website is down. What are the closest alternatives to it? Although this question has been asked on this forum before the answers were unsatisfactory because one or the following things were missing from the suggested alternatives: - 80 question in 8min format: This is not a necessity, but given the fact that optiver tests are genrally in this format it would be an added plus. I basically want a site that is the closest simulator for Optiver's math test. So if there is any additional characteristics you know from your experience of giving the test kindly suggest a resource accordingly. If I have incorrectly assumed something about the test kindly correct me. All this being said, I assume their test has a lot of variations accross countries or time, so I am only looking for the best estimate of what the test will be like. Some websites that do not meet the above criteria are: rankyourbrain.com and arithmetic.zetamac.com ## Answer by trader maths (score 6, accepted) https://quant.stackexchange.com/a/46229 http://tradermaths.com is probably the most similar to Optiver. The site has a Floating point option, penalty for error and 80 questions in 8 minutes. ## Answer by jmh (score 4) https://quant.stackexchange.com/a/53241 I use https://graduatetrader.com/ they have 50 maths tests, each 8 mins long with 80 questions and negative marking. You can also make a profile to log your results. ## Answer by BigChief (score 4) https://quant.stackexchange.com/a/59613 Addition The trick here is to break up “ugly” numbers into round ones: ``` 87 + 94 = (87 + 90) + 4 = 181 334 + 567 = (300 + 567) + 34 = 867 + 30 + 4 = 897 + 4 = 901 ``` Subtraction Subtraction questions are similar, but you need to decide when to round up. For example, if the second number’s second digit is bigger than the first number’s second digit, round up: ``` 62 – 27 = 62 – 30 + 3 = 32 + 3 = 35 845 – 388 = 845 – 400 + 12 = 445 + 12 = 457 ``` Multiplication Multiplying a 2- or 3-digit number by a 1-digit number is straightforward because you just separate them into smaller groupings: ``` 47 x 5 = (40 x 5) + (7 x 5) = 200 + 35 = 235 397 x 4 = (300 x 4) + (90 x 4) + (7 x 4) = 1200 + 360 + 28 = 1588 ``` For 2×2 multiplication, put the number with the larger second digit first and then group them into smaller units once again: ``` 42 x 37 = 37 x 42 = (37 x 40) + (37 x 2) = (30 x 40) + (7 x 40) + (37 x 2) = 1200 + 280 + 74 = 1554 ``` Division Division by 5. Multiply left number by 2 and divide by 10. Squaring 2-Digit Numbers This formula is the trick for squaring 2-digit numbers: X^2 = (X + Y) * (X – Y) + Y^2 And then you set Y such that either (X + Y) or (X – Y) ends with “0.” Examples: ``` 49^2 = (49 + 1) * (49 – 1) + 1^2 = 50 * 48 + 1 = 2500 – (50 * 2) + 1 = 2401 56^2 = (56 + 4) * (56 – 4) + 4^2 = 60 * 52 + 16 = 60 * 50 + 60 * 2 + 16 = 3000 + 120 + 16 = 3136 ``` Square Roots There are fewer “tricks” with square roots because no matter what you do, the answer will usually have decimal places. But you can usually approximate the answer by thinking in terms of square numbers. For example, let’s say they ask you the square root of 90: You know that 9^2 = 81 and 10^2 = 100. And 90 is slightly closer to 81 than 100. So, you can say “slightly less than 9.5” (it’s ~9.49). ## Answer by user39452 (score 3) https://quant.stackexchange.com/a/44847 You can try http://arithmetic.lemo.education/. Here you can actually train decimal calc, which was the hardest obstacle (at least for me). ## Answer by QuantNero (score 3) https://quant.stackexchange.com/a/72100 Personally I would recommend http://tradermath.org because it actually has the exact test format of Optiver, it's multiple choice, 80 questions in 8 minutes with actual emphasis on decimals and fractions - like the real test. ## Answer by Ben (score 2) https://quant.stackexchange.com/a/54439 Check out https://www.tradinginterview.com, it helped me a lot ## Answer by Ali (score 1) https://quant.stackexchange.com/a/74599 It seems like some of the answers above are outdated, so I'll add a recent website that I found which I've been really enjoying for mental math: https://openquant.co/math-game At the moment, they have both arithmetic and sequence-style questions and the great part is that everything is free. ## Answer by schlauLern (score 0) https://quant.stackexchange.com/a/76362 I use https://drillyourskill.com/ because you can also hear the questions instead of just reading. Of course it is not as elaborate
Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.