You can unlock your iPhone for use with different carriers. Unlocking means that you can use your phone with a different carrier. An unlocked phone is sometimes called a SIM-Free or contract-free phone.hen you'll back up, erase, and restore your iPhone to unlock it. Start the process: 1  See if your carrier offers unlocking. 2  Only your carrier can unlock your iPhone. 3  Contact your carrier and request an unlock. 4  You might need to meet requirements to qualify for unlocking.
Rounding policies that everyone agrees with: If you are rounding a number to a certain degree of significant digits, and if the number following that degree is less than five the last significant figure is not rounded up, if it is greater than 5 it is rounded up.
The significant figures of a number are digits that carry meaning contributing to its measurement resolution. This includes all digits except: All leading zeros; Trailing zeros when they are merely placeholders to indicate the scale of the number; and Spurious digits introduced, for example, by calculations carried out to greater precision than that of the original data, or measurements reported to a greater precision than the equipment supports. Significance arithmetic are approximate rules for