Countdown

[Julian]

A girl that from a [distance looks] like a [10 out of 10], until she starts coming closer you then begin the countdown from 10 until shes right up close you [realise] in fact shes only a 2!

[Vania]

the act of counting backwards to zero:

[Julian]

An act of counting numerals in reverse order to zero, especially to time the last seconds before the launching of a rocket or missile.

[Zipporah Schumaker]

Recite or display numbers backward to zero to indicate the time remaining before the launch of a rocket or the start of an operation.