Home / All Definitions / Numbers & Symbols / Truncating a Number Definition

Truncating a Number Definition

Truncating a number otherwise referred to just as truncation is a method of approximating a decimal number by dropping all decimal places past a certain point without rounding. In other terms truncation is limiting the number of digits right of the decimal point. For instance, with pi (π), 3.14159265…, it can be truncated down to 3.1415. In this case, if 3.14159265...were rounded to the same decimal place, the approximation would result in the number 3.1416.


An analogue of truncation can be applied to polynomials. In this case, the truncation of a polynomial P to degree n can be defined as the sum of all terms of P of degree n or less. For instance, Polynomial truncations arise in the study of Taylor polynomials.

Computer Science

With computers, truncation can occur when a decimal number is typecast as an integer. In this case the number getting typecast is truncated to zero decimal digits because integers cannot store non-integer real numbers.

Related Definitions


“Truncation.” Wikipedia, Wikimedia Foundation, 18 Dec. 2019, en.wikipedia.org/wiki/Truncation.


Welcome to Math Converse

Maintenance Icon

Our site is presently undergoing maintenance in order to upgrade the site.

Please be patient and understand that it will take some time to complete this work and random things may not work as intended.


App Icon

Check out our free app for iOS & Android.

For more information about our app visit here!

Browser Extension

Browser Extension Icon

Check out our free browser extension for Chrome, Firefox, Edge, Safari, & Opera.

For more information about our browser extension visit here!

Add to Home Screen

Add to Home Screen Icon

Add Math Converse as app to your home screen.

QR Code

Take a photo of the qr code to share this page or to open it quickly on your phone:

Cite This Page



Copy Link
Cite Page
Google Classroom