what do you mean by significant figure

Significant figures (or significant digits) are the number of important digits in a value or measurement that indicate its accuracy and precision. They include all non-zero digits, zeros between non-zero digits, and trailing zeros if they are after a decimal point or part of a measured value. Significant figures help communicate how precise a measurement is, reflecting which digits are known reliably and which last digit is an estimated or uncertain value. For example, in the number 652.1, there are 4 significant figures, and in 0.0034, there are 2 significant figures. They are essential in scientific and technical fields to avoid overstating the precision of measurements and calculations.