All of these numbers have 3 significant figures right?

[Power of One]

12.5
100.00
105
2.5 x 10^3

All of these numbers have 3 significant figures right?

​

 

[pzona]

No, 12.5 and 105 have three significant figures. Look at the other two again

 

[mgb_phys]

The last one is two sf, three would be 2.50 x10^3

105 is 3sig fig

 

[Power of One]

The last one is two sf, three would be 2.50 x10^3

105 is 3sig fig

I caught that shortly after, thank you.

@pzona- Doesn't 100.00 only have two significant figures, the 1 and the two zeros after the decimal point?​

 

[symbolipoint]

I caught that shortly after, thank you.

@pzona- Doesn't 100.00 only have two significant figures, the 1 and the two zeros after the decimal point?​

100.00 is written to indicate significance to the hundredths place. The number has five significant figures. (from locations of places Hundreds to Hundredths).

 

[pzona]

The way I learned sig figs, there were 3 main rules.

1. Zeros between nonzero digits are always significant (1001, 304)
2. Zeros at the beginning of a number are never significant (0.001, 0.026)
3. Zeros at the end of a number are significant if the number contains a decimal point (e.g. 100.00)

These are pretty easy to remember, and I still find myself going through them in my head every time I need to count significant figures. Hopefully this helps.