China · 429-500
Zu Chongzhi
Zu Chongzhi was mathematician, astronomer, and engineer. He produced an exceptionally accurate rational approximation to pi and worked on calendars and astronomical measurement.
Biographical and historical reference works document Zu Chongzhi’s role and the mathematical work summarized on this page.
3-5, 6-8, 9-12, College
The person and the work
Biography
Zu Chongzhi was mathematician, astronomer, and engineer associated with China. He produced an exceptionally accurate rational approximation to pi and worked on calendars and astronomical measurement.
The fraction 355/113 remained famous for its accuracy and simplicity. Together, these contributions connect number sense, fractions, ratios, and percentages, geometry and measurement, and trigonometry to the working problems, tools, and questions of the period.
Mathematical contribution
What this hero added or preserved
Core mathematical work
He produced an exceptionally accurate rational approximation to pi and worked on calendars and astronomical measurement.
Method, teaching, or application
The fraction 355/113 remained famous for its accuracy and simplicity.
Why this matters
The larger lesson
Zu Chongzhi shows that mathematics grows through proof, calculation, observation, design, teaching, or careful records. The lasting lesson is that number sense, fractions, ratios, and percentages, geometry and measurement, and trigonometry can turn a difficult question into a method another person can inspect and reuse.
Place the work in time
Timeline
- 429
Life and working period
Zu Chongzhi worked as mathematician, astronomer, and engineer in China.
- Legacy
Lasting mathematical connection
The fraction 355/113 remained famous for its accuracy and simplicity.
Key idea
Numbers reveal structure
Zu Chongzhi’s story shows that numbers are not only labels. They can be classified, compared, decomposed, and arranged to reveal patterns.
When 782 is divided by 5, the quotient is 156 with remainder 2. That remainder is structural information, not a mistake.
Try it yourself
Find the quotient and remainder
Divide 782 by 5. State the quotient and remainder.
- Estimate how many full groups fit.
- Multiply the divisor by the quotient.
- Subtract to find the remainder.
Show the answer
782 = 5 × 156 + 2, so the quotient is 156 and the remainder is 2.
Math at work
Engineers and architects use the same habits
Engineers and architects use number sense to plan, compare, test, or communicate decisions. Zu Chongzhi’s work provides a historical example of that connection.
Keep curiosity alive
A little-known fact
The fraction 355/113 remained famous for its accuracy and simplicity.
Zu Chongzhi matters because of only one famous formula or anecdote.
The documented record is broader: He produced an exceptionally accurate rational approximation to pi and worked on calendars and astronomical measurement.
Keep exploring
Connected learning paths
Related math terms
- Place value
- Prime number
- Number pattern
- Ratio
Practice these ideas
- AdditionPractice adding whole numbers, integers, and decimals.
- SubtractionPractice subtracting whole numbers, including results below zero.
- Fractions & DecimalsWork with fractions, decimals, percentages, and conversions.
- Pre-AlgebraBridge arithmetic and algebra with integers, ratios, and equations.
- GeometryExplore shapes, angles, area, perimeter, volume, and classification.