BlackEdge Online Assessment: Mental Math Tests 1 and 2
BlackEdge Capital, the Chicago proprietary trading firm, screens trader applicants with typed mental math. A recent candidate report describes two tests on HackerRank: Test 1 with 15 questions in 7 minutes, a 30-minute break with one typed behavioural answer, then Test 2 with 30 questions in 15 minutes. Questions cover 4-digit addition and subtraction, multiplication, exact division, percentages, square roots and fraction to decimal conversion, with no calculator, and answers are typed rather than picked. Both tests are rebuilt below as timed replicas with a free sample.
BlackEdge mental math test 1: 15 questions in 7 minutes
A replica of the first of BlackEdge's two timed mental math tests: candidates report 15 typed arithmetic questions in 7 minutes with no calculator, covering 4-digit addition and subtraction, multiplication, exact division, percentages, square roots and fraction to decimal conversion.
- 15 questions in 7 minutes, under 30 seconds each; candidates report this as Test 1 on HackerRank
- Typed numeric answers, no calculator and no multiple choice; most questions want the exact answer, and rounded ones state the precision (2 or 3 decimal places, nearest whole number)
- Candidates report (Oct 2026) a 30 minute break with one typed behavioural answer, then Test 2 (30 questions in 15 minutes); 2023 to 2025 versions also had probability items
- Questions ramp from 4-digit addition and subtraction and 2-digit products to exact division, square roots, reverse percentages and chained fractions
- +1 per correct answer, 0 for wrong or blank; move freely between questions
The free sample draws a fresh mix from its own question pool on every retake, separate from the full run, which draws from a larger pool of its own. The review explains every answer.
- Bank the first five quickly: add and subtract thousands first, split products into tens and units, and say the partial sums in your head.
- For square roots, bracket between two perfect squares, take the linear step (n minus r squared) over 2r, then check one square to fix the second decimal.
- For n over 7, 13 or 17, do three steps of long division and look at the fourth digit before rounding; never round twice.
- If a question stalls you past 40 seconds, skip it and come back: the pass bar candidates report is 11 of 15.
BlackEdge mental math test 2: 30 questions in 15 minutes
A replica of BlackEdge's second, longer mental math test: candidates report 30 typed arithmetic questions in 15 minutes with no calculator, the same topic mix as Test 1 but harder on average.
- 30 questions in 15 minutes, 30 seconds each; candidates report this as Test 2 on HackerRank
- Typed numeric answers, no calculator; most questions want the exact answer, and rounded ones state the precision (1 to 3 decimal places, nearest whole number)
- Candidates report (Oct 2026) it comes after Test 1 (15 questions in 7 minutes) and a 30 minute break with one typed behavioural answer; 2023 to 2025 versions also had probability items
- Mix: 4-digit addition and subtraction, 3-digit products, exact and decimal division, odd percentages, compounding, square roots of non-perfect squares, chained operations
- +1 per correct answer, 0 for wrong or blank; move freely between questions
The free sample draws a fresh mix from its own question pool on every retake, separate from the full run, which draws from a larger pool of its own. The review explains every answer.
- Keep a steady 30 second rhythm: if a question will clearly take a minute, skip it and finish the run first.
- Turn percentages into multipliers (a 15% discount is x 0.85) and reverse them by dividing, never by adding the percentage back.
- Cancel common factors before multiplying in chained products; most of them collapse to a 2-digit product.
- Write rounded answers with exactly the decimal places asked: an extra rounding step is the most common lost mark.
Build the speed first
Typed answers remove the safety net of multiple choice: a rounding slip is simply wrong. Short daily sprints on the free drills below build the speed, and the replicas above check the precision each question asks for.
Zetamac practice game: free 2-minute arithmetic sprint →
Sources and how current this is
The two-test format comes from an October 2026 candidate report summarised by an interview prep site; an August 2025 forum report describes a similar HackerRank-style timed test, and 2023 to 2025 versions are reported to have included probability items, with a 20-minute GMAT-style test used before 2023. BlackEdge does not publish its test format, so treat counts and timings as candidate-reported. Every practice question here is original and generated, and every answer is checked by code.
BlackEdge Capital OA: FAQ
What is on the BlackEdge online assessment?
Candidates report two typed mental math tests on HackerRank: 15 questions in 7 minutes, then after a break with one written behavioural question, 30 questions in 15 minutes. Topics are multiplication, exact division, percentages, square roots and fraction to decimal conversion, without a calculator.
Are the BlackEdge answers multiple choice?
No. Reports describe typed numeric answers, so every question states the precision it wants (exact, or rounded to a number of decimal places), and the replicas grade to that precision.
What score do you need on the BlackEdge mental math test?
BlackEdge does not publish a cutoff. Prep sites cite roughly 11 out of 15 on Test 1 and 22 out of 30 on Test 2 as typical pass bars; aim for clean accuracy first, then speed.
Is the BlackEdge practice test free?
Each replica has a free timed sample with no signup that ends in a scored review. The full timed simulations, which draw a fresh mix of questions on every run, are part of QuantVault Pro.
Practice every firm's OA: timed replicas, free game replicas and guides in one place →