Bad Fraction Simplification

Initializing live version
Download to Desktop

Requires a Wolfram Notebook System

Interact on desktop, mobile and cloud with the free Wolfram Player or other Wolfram Language products.

Given the fraction 471428/714285, strike out the 71428 on the top and bottom to get 4/5, which does not equal 471428/714285. This recipe almost never works.


However, 4571428/5714285 does equal 4/5, the result of striking out 571428 on the top and bottom. Very rarely, this bad method of simplification actually works. When it does, there is a repeating decimal of another fraction involved.

Bad fractions can quickly get enormous. One example is 73/81, which uses the repeating decimal of 5913/7219 with length 7218.


Contributed by: Ed Pegg Jr (December 2020)
Open content licensed under CC BY-NC-SA



Feedback (field required)
Email (field required) Name
Occupation Organization
Note: Your message & contact information may be shared with the author of any specific Demonstration for which you give feedback.