Significant Figures - Rounding

Rounding

To round to n significant figures:

  • If the first non-significant figure is a 5 followed by other non-zero digits, round up the last significant figure (away from zero). For example, 1.2459 as the result of a calculation or measurement that only allows for 3 significant figures should be written 1.25.
  • If the first non-significant figure is a 5 not followed by any other digits or followed only by zeros, rounding requires a tie-breaking rule. For example, to round 1.25 to 2 significant figures:
    • Round half up (also known as "5/4") rounds up to 1.3. This is the default rounding method implied in many disciplines if not specified.
    • Round half to even, which rounds to the nearest even number, rounds down to 1.2 in this case. The same strategy applied to 1.35 would instead round up to 1.4.
  • Replace non-significant figures in front of the decimal by zeros.

Read more about this topic:  Significant Figures

Famous quotes containing the word rounding:

    The past absconds
    With our fortunes just as we were rounding a major
    Bend in the swollen river; not to see ahead
    Becomes the only predicament when what
    Might be sunken there is mentioned only
    In crabbed allusions but will be back tomorrow.
    John Ashbery (b. 1927)

    People forget that it is the eye that makes the horizon, and the rounding mind’s eye which makes this or that man a type or representative of humanity with the name of hero or saint.
    Ralph Waldo Emerson (1803–1882)

    I look for the new Teacher that shall follow so far those shining laws that he shall see them come full circle; shall see their rounding complete grace; shall see the world to be the mirror of the soul; shall see the identity of the law of gravitation with purity of the heart; and shall show that the Ought, that Duty, is one thing with Science, with Beauty, and with Joy.
    Ralph Waldo Emerson (1803–1882)