Street-Fighting Mathematics
Street-Fighting Mathematics by Sanjoy Mahajanby Sanjoy Mahajan
Shares rank 7 of 19 mathematics books by recommenders
People recommend it as a readable maths text that teaches estimation tricks rarely taught in university classes.
6 people recommended Street-Fighting Mathematics by Sanjoy Mahajan in Hacker News comments and 1 criticized it, November 2025 to October 2026.
4 of the 6 people who recommend it commented in one thread, “Street-Fighting Mathematics (2008)”.
Summary written by Claude from 6 comments.
7 people gave an opinion
- recommend it
- 6
- mixed feelings
- 0
- warn against or regret it
- 1
The record
Recommended in 3 of 12 months
In 3 different threads.
- November 2025: not recommended
- December 2025: not recommended
- January 2026: recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: not recommended
- May 2026: not recommended
- June 2026: not recommended
- July 2026: recommended
- August 2026: not recommended
- September 2026: recommended
- October 2026: not recommended
Why it doesn’t carry the badge
- 6 people recommend itNeeds 10 or more, not met.
- 6 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 3 of 12 monthsNeeds 4 or more, not met.
- Recommended in 3 threadsNeeds 5 or more, not met.
- 4 of its 6 recommenders came from one threadNeeds half or less, not met.
The same rules apply to every product, and the badge can’t be bought. Mixed feelings count toward neither side. How the badge works
What people say about it
Reasons grouped from a sample of 6 of the 7 opinions about it, picked in proportion to how many people recommend it, have mixed feelings and criticize it. Each mark is one comment in the sample. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Readable, interesting approach to thinking
“It's definitely one of the more interesting and readable maths texts out there.”
Comment from 1 Jan 2026 in “Street-Fighting Mathematics (2008)” “always liked that way of thinking”
Comment from 4 Jan 2026 in “Street-Fighting Mathematics (2008)” Well-liked work by Sanjoy Mahajan
“Even in such goodness as Sanjoy Mahajan's Art of Insight and Street-Fighting”
Comment from 16 Sep 2026 in “Gemini 3.8 Live and 3.8 Live Extended Thinking” “Loved taking this Sanjoy Mahajan's course on OCW in high school”
Comment from 19 Jul 2026 in “The Art of Insight in Science and Engineering – Mastering Complexity(2014) [pdf]”
Other mathematics books people recommend
The four most recommended other mathematics books, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Mixed | Criticize | Approval | Months | Had for | Badge |
|---|---|---|---|---|---|---|---|
| Elements by Euclidby Oliver Byrne | 14 | 2 | 9 | 61% | 8 | — | — |
| Fermat's Last Theoremby Simon Singh | 11 | 0 | 0 | 100% | 3 | — | — |
| Gödel's Proofby Nagel and Newman | 9 | 0 | 1 | 90% | 2 | — | — |
| Mathematica: A Secret World of Intuition and Curiosityby David Bessis | 8 | 0 | 0 | 100% | 6 | — | — |
| Street-Fighting Mathematicsby Sanjoy MahajanThis page | 6 | 0 | 1 | 86% | 3 | — | — |
What people said
6 of the 7 opinions about it, picked in proportion to the three counts, newest first. Each links to the original comment.
“Even in such goodness as Sanjoy Mahajan's Art of Insight and Street-Fighting”
“Loved taking this Sanjoy Mahajan's course on OCW in high school”
“always liked that way of thinking”
“aimed at getting people who haven’t read their pile of books to buy another”
“It's definitely one of the more interesting and readable maths texts out there.”
“useful tricks you can usually not learn in university classes”
Counts come from 1,791,911 Hacker News comments labeled by Claude, November 2025 to October 2026, with data through October 31, 2026. Counts updated 2 Nov 2026. How we count. Report a mistake.