Math.Truncate problem

[elliot5]

how is the following possible?

Print(SizeESgwugES); //= Math.Truncate(SizeESGWupgapmod); = on the print -10
Print(Math.Truncate(SizeESGWupgapmod)); = on the print +10

How using the same double variable "SizeESGWupgapmod" can the sign change?

Regards and many thanks for assistance

[elliot5]

Problem solved. Was interfering code elsewhere. Glad of that because would have been very strange! Regards to all.