Numbers can be rounded to significant figures. Numbers which are significant are usually non-zero numbers. Zeros can become significant however under two conditions.
Part of MathsNumerical skills
Round 50 790 to 2 significant figures.
Find the second significant figure from the number above:
50 790
This is the zero between the 5 and the 7.
As the digit to the right is a 7, then it goes up by one, which changes the 0 to a 1.
Therefore 50 790 rounds to 51 000 to 2 significant figures.
Now try the example questions below.
Round 0.0300 to 1 significant figure.
Find the first significant figure from the number above:
0.0300
As the digit to the right is a 0, then the 3 will stay the same.
Therefore 0.0300 rounds to 0.03 to 1 significant figure.
Round 245 790 to 2 significant figures.
Find the second significant figure, which is 4.
As the digit to the right is a 5, then the 4 goes up by 1 and this changes the 4 to a 5.
The correct answer is therefore 250 000.
Round 69.50 to 1 significant figure.
Find the first significant figure, which is a 6.
As the digit to the right is a 9, then the 6 will go up by 1 and this changes the 6 to a 7.
The correct answer is therefore 70.