Define significant figures.

(N/A) Significant figures are meaningful digits in a measured or calculated quantity. They indicate the precision of a measurement,which depends on the least count of the measuring instrument.
Rules for determining significant figures:
$1$. All non-zero digits are significant.
$2$. Zeros preceding the first non-zero digit are not significant. They indicate the position of the decimal point.
$3$. Zeros between two non-zero digits are significant.
$4$. Zeros at the end or right of a number are significant,provided they are on the right side of the decimal point.
$5$. Counting numbers of objects,for example,$2$ balls or $20$ eggs,have infinite significant figures as these are exact numbers.