Study Notes
Estimation involves simplifying numbers while maintaining their overall meaning, making them easier to use but less precise. It includes rounding whole numbers and decimals to a certain degree of accuracy.
- Rounding — simplifying a number while keeping its meaning similar. Example: 630 rounds to 600 or 700.
- Decimal Rounding — rounding decimal numbers to wholes, tenths, or hundredths. Example: 152.836 rounds to 153 (whole), 152.8 (tenths), 152.84 (hundredths).
- Significant Figures — the first non-zero digit in a number. Example: The first significant figure of 5263 is 5.
Exam Tips
Key Definitions to Remember
- Rounding: Simplifying a number while keeping its meaning similar.
- Decimal Rounding: Rounding decimals to wholes, tenths, or hundredths.
- Significant Figures: The first non-zero digit in a number.
Common Confusions
- Confusing rounding up with rounding down.
- Misidentifying the first significant figure.
Typical Exam Questions
- Round 59.1256 to the nearest whole number? Answer: 59
- What is 0.56×0.2 rounded to 2 decimal places? Answer: 0.11
- Round 6.82146 to 2 significant figures? Answer: 6.8
What Examiners Usually Test
- Ability to round numbers to different levels of precision.
- Understanding of significant figures and their application.
- Application of rounding in calculations.