04 – Significant figures (sf)

What are Significant figures:

 

Another method of approximating an answer is to round off using significant figures.

 

With the number 738,249, the 7 is the most significant digit, because it tells us that the number is 7 hundred thousand and something. Then the 3 is the next most significant, and so on.

 

With the number 0.00321, the 3 is the most significant digit, because it tells us that the number is 3 thousandth and something. Then the 2 is the next most significant, and so on.

 

Be careful with numbers with a zero, such as 90123, the 9 is the first significant figure and 0 the second, because of its value as a place holder.

 

Round off a number to a certain number of significant figures, usually to 1, 2 or 3 significant figures.


Your Turn:

 

What is 1.99 correct to 2 sfs?

Enter your answer here:

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