It was stated in a newspaper that
the attendance at the MCG(Melbourne Cricket Ground) for a football match was 64,000. But a
friend who was attending the same match said the crowd was 64,492. The information from
both sources are correct, but it was given to a different degree of accuracy.

64,492 might have been the exact number. When we round off 64,492 to two significant
figures, it is 64,000.

The first non-zero digit, reading
from left to right in a number, is the first significant figure.

**e.g. In 64,492 , 6 is the
first significant figure.(sig.fig.) When we round off 64,492 to two sig. figs, that means
in the answer we should have two non zero figures.The third figure(which is 4) is less
than 5, so we drop them to zeros.**

**Let's round off 64,492 to:**

(a) **1 **significant figure ** **** which is 60,000**

(b) **2** significant
figures ** **** which is 64,000**

(c) **3 **significant figures ** which is 64,500**

(d)** 4** significant figures** **** which is 64,490**

(e) **5 **significant figures ** ****which is 64,492**

**The accuracy of the answer
will depend on the number of significant figures.** **The answer will be more
accurate, if it is given to a higher number of significant figures**.

**64,492 is
the most accurate answer and it is given to 5 sig. figs.**

***** The trailing zeros in a whole number are not
significant.There are used to keep the other figures in there correct places.**

eg. 64000 6 and 4 are significant not the
zeros.

***** The leading zeros in a decimal are not significant. There are
used to keep the other figures in there correct places.**

eg. 0.000054 , only 5 and 4 are significant.

*****The zeros between the figures are significant.**

eg. 30.05 each figure is significant. There are 4
sig.figs.

***** The last zero in a decimal is significant.**

**eg. 3.20each figure is significant. There are **

3sig.figs.

eg. 0.50, 5 and last zero are significant.There are

2 sigfigs