Mental Math Practice
Arithmetic speed drills. Start with today's free daily set, then take a full firm-style speed test: 80 in 8, Flow Traders, Maven Securities or SIG. No signup. Runs in your browser.
2-minute warm-up or full 8-minute test
Daily Mental Math
20 questions · 2 minutes · today's set
+1 per correct answer, −1 per wrong answer, skips are free. Everyone gets the same 20 questions today.
Four mental math methods, worked through
These original examples are available before starting a test. Learn the steps without a timer, then use the daily drill to practice under its two-minute clock. This drill awards +1 for a correct answer, −1 for a wrong answer and 0 for a skip; its target is a practice goal.
Multiply by splitting one number
Question: What is 17 × 24? Answer: 408. Split 24 into 20 + 4. Then 17 × 20 = 340 and 17 × 4 = 68; add them to get 408. The distributive rule lets you choose the split that makes the two products easiest.
Common error: forgetting one of the two products or using 17 × 2 without restoring the factor of 10. Check that the result lies between 17 × 20 = 340 and 17 × 25 = 425.
Convert a fraction using a familiar denominator
Question: Write 5/8 as a decimal. Answer: 0.625. Multiply the numerator and denominator by 125: 5/8 = 625/1000. Alternatively, 1/8 = 0.125, so five eighths is five times 0.125.
Common error: placing the decimal one digit too far left or right. Five eighths is greater than one half and less than three quarters, so the decimal must be between 0.5 and 0.75.
Apply successive percentage changes
Question: A value of 200 rises by 10%, then falls by 10%. What remains? Answer: 198. The rise gives 200 × 1.10 = 220. The fall takes 10% of 220, or 22, leaving 198. Equivalently, 200 × 1.10 × 0.90 = 198.
Common error: cancelling the percentages. They apply to different starting values. For the reverse calculation, see the CTC-style discount-and-fee example.
Use an estimate to catch a magnitude error
Question: What is 49 × 21? Answer: 1,029. First estimate 50 × 20 = 1,000. For the exact result, use (50 − 1) × 21 = 1,050 − 21 = 1,029. An estimate near 1,000 catches an accidental answer such as 102.9 or 10,290.
Common error: submitting the rounded estimate when an exact answer is required. Estimation checks the size of an answer; it does not replace the calculation.
Next: start the 20-question daily arithmetic drill, or use the fixed 80-question, 8-minute practice test for a longer run. Both show their scoring rules before you start.
Firm mental math tests
The settings below describe our independent practice simulators. Each uses one fixed set, so keep first attempts separate from retakes when comparing scores. Use your actual invitation for recruitment rules.
80 in 8 Mental Math Speed Test
80 arithmetic questions · 8 minutes · typed answers · −1 per wrong answer. TradeMind practice target: 60 net on this 80Q / 8-minute set (not a firm cutoff).
Optiver-styleAkuna Capital Math Test
80 typed questions · 8 minutes · −1 per wrong answer. A different fixed practice set from the Optiver-style page.
Akuna-style 80-in-8Flow Traders Math Test
75 multiple-choice questions · 8 minutes · −2 per wrong answer. TradeMind practice target: 70 net on this 75Q / 8-minute configuration (not a firm cutoff).
Training configurationMaven Securities Math Test
40 five-choice questions · 6 minutes · −2 per wrong answer · practice target of 34 correct. Candidate-reported practice benchmark: ~34 correct on a reported 40Q / 6-minute format (not an official cutoff).
Shortest formatSIG Online Assessment
70 questions · 8 minutes · typed and multiple choice. Covers difference-of-squares tricks, decimal magnitude and ugly fractions. TradeMind practice target: 55 net on this 70Q / 8-minute configuration (not a firm cutoff).
Trick recognitionMulti-section OA practice
Our CTC-style simulation mixes numerical, spatial, verbal and logic reasoning, a broader practice format than arithmetic speed. See Realistic OA Trials.
Questions
What's the difference between the daily drill and the firm tests below?
The daily drill is short (20 questions, 2 minutes) and generic. Everyone gets the same set on a given day, and it changes the next day, so it suits a short daily session. The firm-style tests below (80 in 8, Flow, Maven, SIG) use longer TradeMind practice configurations. Each is one fixed set that never changes, so treat it as a one-off full-length attempt.
Why is the daily set the same for everyone?
The daily drill rotates through a fixed 180-day pool. Everyone gets the same questions on the same day. Record a first attempt separately from a retake, because remembering an answer can improve a score without improving arithmetic.
Which firm test should I practice?
If you don't know your target firm yet, start with 80 in 8. Public reports link Optiver and Akuna to versions of that format. Flow, Maven, and SIG use variants that can change by region, role, and recruiting cycle, so check your invitation for the current rules.
Is this the same as a firm's full online assessment?
No. These are arithmetic speed drills. For a multi-section OA that mixes numerical, spatial, verbal and logic reasoning (like CTC's), see Realistic OA Trials.