Integers ending in zero(s) are ambiguous. There is no way of telling whether the measurement was taken to the nearest metre and expressed in cm (1 significant digit) or measured to the nearest centimetre (3 sig fig).
1 of them.
How many significant figures are in the measurement 210 cm?
There are 4 significant figures in this number.
There are 2 significant figures in this measurement.
There are 3 significant figures
3 of them.
How many significant figures are in the measurement 210 cm?
5 significant figures.
There are 4 significant figures in this number.
There are 2 significant figures in this measurement.
4.05 has three (3) significant figures
There are 3 significant figures
None. The abbreviation cm represents one or more centimeters. In your question there are no numbers associated with the cm unit, therefore there are no significant figures.
2 of them.
12.655 cm rounded to four significant figures is 12.66cm
This has 4 significant figures, and they are 6420
3 of them.
Four.