APPROXIMATION
CONTENT
- Rounding Off Numbers (Rounding Up and Rounding Down)
- Approximating the Results of Addition and Subtraction
- Approximating the Result of Multiplication and Division
Rounding Off Numbers
Sometimes, when we perform mathematical calculations, the result may give rise to many more digits than is required. We may approximate the result by giving it a smaller number of significant figures or decimal places. This is called rounding off. Rounding off numbers may involve rounding up or rounding down. The last digit to be ignored is usually the clue to rounding up or rounding down the last digit that is kept. If the last digit to be ignored is \(5\) or more, the last digit to be kept is increased by \(1\); if it is less than \(5\), it remains unchanged. In doing this, however, the number that is being rounded off must be close to the original as possible.
Examples:
1. Round off the following to
(i) \(2\) significant figures.
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ClassHall Instructor
Ezimeruwe Oghenekaro
Halima Ahmadu
Sadiq Barau