Estimation and approximations
Round appropriately and interpret the range and error of an estimate.
Meaning
Estimation expresses a number more simply at a suitable precision. Rounding to nearest uses the next lower digit to choose the nearer rounded value.
Example
347 rounded to the nearest ten is 350. The absolute difference from the original value is 3. The neighboring tens are 340 and 350. Since 347 is 7 from 340 and 3 from 350, choose 350. For positive numbers exactly halfway, the usual school convention rounds upward. A rounded value need not equal the original. Check whether a bound is included: “at least” differs from “greater than.”
Practice for this concept
Scope and references
Topics
Rounding up, rounding down, rounding to nearest, inclusive and strict bounds, estimates and error
Learning goal
Round appropriately and interpret the range and error of an estimate.
Helpful background
Explore place value and the distance between numbers.
Rounding to the nearest ten
Does not include rounding up, rounding down, or rounding to other places.