Mathematics for IGCSE & O level - Estimation (Section 2 - No. 44)
What is a significant figure?
Any digit in a number.
A digit that is not zero.
A digit that is not a zero used only to locate the decimal point or show place value.
The first digit in a number.
Paliwanag
Significant figures are counted from left to right, starting with the first non-zero digit. Zeros used to maintain the place value are not significant figures.