APPROXIMATION

CONTENT

1. Rounding off Numbers to the Nearest Whole Numbers, \(10, 100, 1000, 0.5, 0.1,\) etc.
2. Application of Approximation in Everyday Life
3. Quantitative Reasoning

Rounding off Numbers to the Nearest \(10, 100\) and \(1000\)

You recall that powers of ten as \(10^1, 10^2, 10^3\) are \(10, 100, 1000\) etc. respectively. When rounding off to any of these powers of ten, numbers half or above half of \(10\) are rounded off by adding one to the required digit, while the remaining lower digits are dropped to zero.

Example 1

Round off \(253 \text{ } 718\) to the nearest thousand.

Solution

The thousands digit is \(3\), and the digit before it is \(7\).

Since \(7\) is higher than \(5\), hence it is rounded up to \(10\) and \(1\) is added to \(3\) to become \(4\), and the remaining digits are replaced with \(zero\). That is;

\(253 \text{ } 718 = 254 \text{ } 000\) to the nearest \(1 \text{ } 000\). This is because \(718\) is nearer to \(1 \text{ } 000\) than \(418\) or \(7\) is nearer to \(10\) than it is to \(zero\).