Answer:
The smallest possible number this could have been = 455500
Step-by-step explanation:
456000 has been rounded to the nearest thousand.
If the value is more than 456500 the value rounded to the nearest thousand is 457000.
If the value is less than 455500 the value rounded to the nearest thousand is 455000.
In between 455500 and 456500 the value rounded to the nearest thousand is 456000.
So, The smallest possible number this could have been = 455500