MathematicsExam code: 0580
Rounding, Estimation and Bounds
Number
Rounding to a Place Value
The rule
- Locate the digit sitting in the place value being rounded to
- Look at the single digit immediately to its right, and ignore everything beyond it
- That digit decides the direction: 5 or more rounds up, 4 or less leaves the digit unchanged
- Fill every place between the rounded digit and the decimal point with zeros, since dropping them would change the size of the number
- 4826 to the nearest hundred is 4800
- 4872 to the nearest hundred is 4900