How Many Significant Figures Are in 100?
100= 1 significant figure (minimum)
Why 100 has 1 sig fig
100 is written without a decimal point, so its trailing zeros are ambiguous. The only digit we can say with certainty is significant is the 1. The two trailing zeros may or may not be significant depending on the context and precision of the original measurement.
Rule applied
Trailing zeros in whole numbers without a decimal point are ambiguous (Rule 5). See full rule →
How to remove the ambiguity in 100
⚠️ This number is ambiguous as written
To show 100 has 3 sig figs, write 100. (with a decimal point) or 1.00 × 10². To show 2 sig figs, write 1.0 × 10².