In mathematics and computer science, truncation is the process of limiting the number of digits to the right of the decimal point. It is a method of approximating a decimal number by removing all decimal places beyond a certain point without rounding. To truncate a number, we omit digits beyond a certain point in the number, filling in zeros if necessary to make the truncated number approximately the same size as the original number. The Math, trunc() function returns the integer part of a number by removing the fractional digits.

Truncation is commonly used when dealing with large numbers or when precision is not required. For example, when dealing with large numbers, it may be necessary to truncate them to make them easier to work with. In this case, the truncation of a polynomial P to degree n can be defined as the sum of all P terms of degree n or less. Truncation can also be used when dealing with decimal numbers.

In this case, it is common for stage 3 to be omitted and for a number such as 3547 to be truncated to 35 to 2 significant digits. To truncate a number to 3 significant digits, omit all digits after the first 3 significant digits (the first non-zero digit and the next two digits). With computers, truncation can occur when a decimal number was typecast as an integer; it is truncated to zero decimal digits because integers cannot store non-integer real numbers.