WASHINGTON (AP) — President Joe Biden's opening months in office have been a whirlwind of activity during the pandemic and the start of an economic recovery. He is facing a sharp increase in the number of migrant children at the U.S.-Mexico border, the tragedy of mass shootings and lingering tensions over racial inequities, the environment and the legacy of his predecessor, Donald Trump.

A look at some defining numbers from his first 100 days in office:

2.67 million – Average number of vaccines administered daily during the past week, up from roughly 1.5 million when Biden was inaugurated.

4,3...