Retrieval, not recognition
Produce the answer yourself before you see the method.
Mental math, made useful
Make numbers
feel familiar.
Ten focused questions. Clear explanations. No countdown making your thinking noisy.
Start a free workout10-question workout
Think clearly. Answer calmly.
Question1 / 10
Score0
0 streak
subtraction
14 − 7
Press Enter to check. No timer—accuracy comes first. Progress stays in this browser
Built for durable recall
Practice that
shows its work.
Explanations that help
Every miss reveals a short route to the exact answer.
Private progress
Session totals stay on this device in localStorage.
A quick way to find 15%.
Find 10%, then add half of that amount. For 15% of 80: 10% is 8, 5% is 4, and 8 + 4 = 12.
Train number sense
Good mental math is not a bag of tricks. It is seeing friendly parts inside an unfamiliar problem.
Start with accuracy. With repetition, useful decompositions become automatic and speed follows without forcing it.
Try another workoutMental math questions
Is this mental math practice free?
Yes. Every workout is free, works without an account, and runs entirely in your browser.
Why is there no timer?
The default workout prioritizes accurate retrieval and useful explanations. Speed can improve without making every question stressful.
What skills can I practice?
The first release includes mixed arithmetic, addition, multiplication, subtraction inside mixed sets, and percentage questions.
Where is my progress stored?
Only in this browser's localStorage. It is not uploaded or automatically synchronized to another device.