Rounding Numbers: Principles and Examples
This page provides a comprehensive overview of rounding numbers, covering natural numbers, decimals, and various levels of precision. It offers numerous examples to illustrate the concepts.
Definition: Rounding is the process of reducing the precision of a number by replacing it with the closest value of specified precision.
Natural Numbers: The page begins with examples of rounding natural numbers to thousands:
- 4000 remains 4000
- 730 rounds to 1000
- 69 rounds to 0
- 2137 rounds to 2000
Example: When rounding 2137 to thousands, we look at the hundreds digit (1). Since it's less than 5, we round down to 2000.
Rounding to hundreds is also demonstrated:
- 500 remains 500
- 499 rounds to 500
- 1000 remains 1000
Decimal Numbers: The page then moves on to rounding decimal numbers, providing examples for rounding to tenths, hundredths, and thousandths.
Highlight: When rounding decimals, pay attention to the digit immediately to the right of the desired rounding position.
Examples of rounding to tenths:
- 3.48 rounds to 3.5
- 7.72 rounds to 7.7
- 9.948 rounds to 9.9
Vocabulary: Zaokrąglanie liczb 0,5 refers to the rule that when the digit to be rounded is exactly 5, it's typically rounded up.
Examples of rounding to hundredths:
- 4.298 rounds to 4.30
- 5.673 rounds to 5.67
- 6.832 rounds to 6.83
Examples of rounding to thousandths:
- 7.246 remains 7.246
- 2.994 remains 2.994
- 1.54745 rounds to 1.547
Highlight: The page emphasizes that it's common practice to underline the last digit that is kept after rounding.
The page concludes with examples of rounding to whole numbers, tens, and hundreds, reinforcing the principles across different scales of numbers.