Brush up your maths: answer to decimals and computers exercise

What is meant by 7.453E+6? What is meant by 7.453E–6? Which of these numbers might be a computer representation of 5: 5.000001, 5.100000, 4.999999, 4.0999999?

7.453E+6 means we move the decimal point six places to the right: 7,453,000.

7.453E–6 means we move the decimal point six places to the left: 0.000007453.

A computer might represent 5 as 5.000001 or 4.999999. How ever many decimal places we round these to, we will get 5.

A computer would not represent 5 as 5.100000 or 4.0999999. If we round these to fewer decimal places, we do not get 5 until we have no decimal places at all.


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