Check out the refreshed revision resources for GCSE Maths: What is truncation?, with step-by-step slideshows, quizzes, practice exam questions, and more!

When we truncate a number, we find an estimate for the number without doing any rounding. To truncate a number, we miss off digits past a certain point in the number, filling-in zeros if necessary to make the truncated number approximately the same size as the original number.

To truncate a number to 1 decimal place, miss off all the digits after the first decimal place.

To truncate a number to 2 decimal places, miss off all the digits after the second decimal place.

To truncate a number to 3 significant figures, miss off all the digits after the first 3 significant figures (the first non-zero digit and the next two digits). Fill in any spaces with zeros to make the number approximately the same size as the original value.

Examples

Truncate 3.784 to 1 decimal place and 2 decimal places.

3.7|84 truncated to 1 decimal place is 3.7

3.78|4 truncated to 2 decimal places is 3.78

Truncate 63,854 and 0.04988 to 3 significant figures.

63,8|54 truncated to 3 significant figures is 63800

0.0498|8 truncated to 3 significant figures is 0.0498