Mathematics for IGCSE & O level - Estimation (Section 3 - No. 25)
When are zeros significant?
At the beginning of a decimal number.
Between non-zero digits.
At the end of a decimal number.
At the end of a whole number, with a decimal point.
Forklaring
Zeros are significant when they are between non-zero digits, at the end of a decimal number, or at the end of a whole number with a decimal point.