Disable android system update to 4.4.2

You can disable system update notification on your android device by going to

Settings - > Apps - > Google services framework - > un-tick show notifications.

then Clear data
and Clear cache

Evaluate excel formula errors

IFERROR function return the value that you specify when a formula evaluates to one of the following errors:

• #N/A
• #VALUE!
• #REF!
• #DIV/0!
• #NUM!
• #NAME?
• #NULL!

IFERROR(Value / formula that is evaluated, Value_if_error)