When we truncateApproximating a number by missing off digits past a certain point, without rounding. 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.
A calculator display often truncates numbers, eg:
\(\frac{2}{3}\) is sometimes displayed as 0.666666666, which is truncated because it is a recurring decimal. If it were rounded, it would be 0.666666667.
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
Question
Truncate 0.1845 to 1 and 2 decimal places.
0.1|845 truncated to 1 decimal place is 0.1
0.18|45 truncated to 2 decimal places is 0.18
Question
Truncate 604,758 to 2 significant figures and 3 significant figures.
60|4,758 truncated to 2 significant figures is 600,000
604|,758 truncated to 3 significant figures is 604,000