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:

    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)

    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)

    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)