Depending on what you're trying to achieve:
{=INT(7123*2/100)*100}
{=ROUND(7123*2,-3)
plus your switch.
To see how to do this and a wide range of other calculations in Word, check out my
Microsoft Word Field Maths Tutorial, in the 'Sticky' thread at the top of this forum:
https://www.msofficeforums.com/word/...-tutorial.html