To put that in perspective, that is approximately the population of Nevada.
Or, the population of Wyoming, Vermont, North Dakota, and Alaska put together.
Or, more than the entire Greater Portland Metropolitan Area.
Or, the cities of Dallas and San Diego combined.
There are only three cities in the US with more than 2.5 million people: New York, Los Angeles, and, just barely, Chicago. If you emptied the entire city of Chicago to house those children, you'd have a few beds left over.