What the trainer does
You choose an operation and a level, and for sixty seconds the trainer serves one question at a time. Type the answer, press Enter, and the next appears. At the end you see how many you answered, how many were right, your average time per question, and a list of every question with your answer beside it. Wrong answers are highlighted so you can see which kinds of sum slow you down.
Three levels
- Warm up. Single digits and low double digits. Tables to 9. Good for getting back into the habit.
- Everyday. Two-digit addition and subtraction, tables to 12. The range of most daily life: splitting bills, checking change, scaling a recipe.
- Stretch. Three-digit addition and subtraction, and two-digit by one-digit multiplication. The range that numerical reasoning tests and case interviews use.
Getting faster
Speed in mental arithmetic comes from working left to right, rounding and adjusting, and knowing a handful of multiplication shortcuts cold. The mental maths guide explains each method with examples and suggests a practice plan measured in minutes rather than hours.
Common questions
What level should I start at?
Start at level 2. If you get more than 90% right with time to spare, move up. If you are under 60%, drop to level 1 for a few sessions and build up. Accuracy first, then speed.
How often should I practise?
One or two sixty-second rounds a day beats a long weekly session. Spaced practice is remembered better, and short sessions are easy to keep up.
Is this useful for consulting or quant interviews?
Yes, as a warm-up. Level 3 covers three-digit addition and subtraction and two-digit multiplication, which is the range case interviews and numerical tests tend to use. Combine it with estimation practice: round, calculate, then adjust.
Are my results saved?
No. Everything runs in your browser and disappears when you leave the page.