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**Rounding Off** - Definition, **Rules**, Examples

... **length** measured, etc are estimated by **rounding off** the actual **number** to the ...
**Rounding off numbers** is done to preserve the **significant figures**. ... **Rounding**
**rules** for **decimal numbers** are as follows: ... Since the **digit** in the smallest place is
less than 5, **round** down has to be done ... time definition **physics** · standard **units**.

For more information, see **Rounding Off** - Definition, **Rules**, Examples

Significant digits or significant figures are the reliable digits plus the first uncertain digit.

The rules for calculating the number of significant figures

- All of the non-zero digits are significant.
- All zeros between two non-zero digits are significant, regardless of where the decimal point is, if it exists at all.
- A change in units has no impact on the number of significant digits or figures in a measurement.
- The preceding or trailing zero(s) in a number without a decimal point are insignificant.
- In a number with a decimal point, the trailing zero(s) are significant.
- If the number is less than one, the zero(s) to the right of the decimal point but to the left of the first non-zero digit are not significant.

a) 0.007 m^2

Significant figures = 1

b) 2.64* 10^{24} kg

Significant figures = 3

c) 0.2370 gcm^{-3}

Significant figures = 4

d) 6.230 J

Significant figures = 4

e) 6.032 Nm^{-2}

Significant figures = 4

f) 0.0006032 m^2

Significant figures = 4