Idioms and Phrases with how about that?
how about that?
Isn't that surprising, remarkable, or pleasing. For example, They're engaged—how about that? [Colloquial; first half of 1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.