Rounding off to the correct number significant figures

[Indranil]

1. The problem statement, all variables, and given/known data
If we add 3.46 and 2.3 we get 5.76.
we can round it to two significant numbers 5.8 because there is the least two significant digit 2.3 but If we add 2.3 X 10^4 + 1.6 X 10^3 = 2.3 X 10^4 + .16 X 10^4 = 2.46 X 10^4. Here can we round off to two significant figures (2.5 X 10^4) because there is also the least two significant digit 2.3 present? Please explain.

Homework Equations

Same as above

The Attempt at a Solution

1. 3.46 + 2.3 = 5.76 rounded off to 5.8
2. 2.3 X 10^4 + 1.6 X 10^3 = 2.3 X 10^4 + .16 X 10^4 = 2.46 X 10^4
If I round it off, then what will be the answer and why?

 

[phinds]

If I round it off, then what will be the answer and why?

What do YOU think it should be, and why?

 

[Indranil]

What do YOU think it should be, and why?

I think it should be 2.5 X 10^4 because there is the least decimal number which is 2.3.

 

[phinds]

I think it should be 2.5 X 10^4 because there is the least decimal number which is 2.3.

I agree