80 in 8 practice: a trading-interview math drill
The 80 in 8 format is a timed arithmetic test: 80 questions in 8 minutes, which is 6 seconds a question. Some trading firms use tests like it to screen candidates. This drill mirrors the pace with whole numbers, decimals and halves; it is practice only, not any firm's real test.
Do it in your head: Split and combine
- Split the two-digit number into tens and ones.
- Multiply each part by the one-digit number.
- Add the two products.
The presets
| Preset | What comes up | Time |
|---|---|---|
| Classic | +, −, × and ÷ | 2 minutes |
| Business % | percents of round amounts | 2 minutes |
| Squares | 2² to 30² | 60 seconds |
| 80 in 8 | 80 questions, with decimals | 8 minutes |
That’s the idea. Keep going: 4 warm-up problems, no sign-up →
Learn it properly: Bigger multiplication →
Questions
What pace do I need?
6 seconds a question on average: 10 questions a minute. After 4 minutes you should be near question 40.
Is this the Optiver test?
No. This is a free practice drill in the same format: 80 questions, 8 minutes. It is not affiliated with Optiver or any trading firm, and the real tests vary.
What kinds of questions come up?
Addition and subtraction with numbers up to 999, multiplication up to 20 × 100, division that comes out whole, and decimals: tenths added and subtracted, numbers like 0.25, 1.5 and 2.5 times a whole number, and halves like 37 ÷ 2.
Should I guess?
Here a wrong answer just waits for the right one, and Skip moves on. Practice accuracy first; speed follows.
How do I get faster?
Split products into tens and ones (7 × 46 = 280 + 42), round and adjust (29 × 4 = 120 − 4), and practice a few minutes every day.