Concepts

Rounding is approximating a number to a given place value.

Rules

Consider the place value you are rounding the number to.

If the digit in that place value is followed by 5,6,7,8, or 9, round the number up.

If the digit in that place value is followed by 0,1,2,3, or 4, round the number down.

Example

Round 33,725 to the nearest ten thousand. 

Solution

Round 33,725 to the nearest ten thousand.

Decide which whole number the given number is closest to using the number line. The answer is 30,000.

Alternate Method: Consider the place value. The number is being rounded to ten thousand. Either round the number up to 40,000 or down to 30,000. If the digit in the thousands place is less than 5, then round the number down to 30,000. Otherwise, round the number up to 40,000.

The answer is 30,000.

Prerequisite Skills

Place value (Grade 4.1.8)

Plotting numbers on a number line  (4.15.8 points on a number line)