How much is 45?
It's about one-fifth the number of Professional Baseball Teams in the United States

The count of Professional Baseball Teams in the United States is about 276.
(2016 figures) (includes Major, Minor, and Independent Leagues)
Nicknamed "America's pastime," there are 276 professional baseball teams in the United States (across all levels of play). Major League Baseball — the league with the highest level of professional play — drew more than 74 million spectators at gmes in 2013.
It's about one-tenth the number of Beatles Songs
The count of Beatles Songs is about 309.
(a.k.a. The Beatles) (1958 thru 1996)
It's about one-tenth the number of a Manned Flights to Space
The count of a Manned Flights to Space is about 312.
(2016 figures) (flights with at least 80km altitude; US, Russia, the Soviet Union, and China)
Since the flight of the Vostok 1 in April, 1961, there have been a total of 312 manned spaceflights under the American, Russian, Soviet, and Chinese space programs. Furthermore, the space programs of the US, Russia, the Soviet Union, France, Argentina, and Iran have launched a total 32 monkeys (specifically rhesus, cynomolgus, and squirrel monkeys, macaques, chimpanzees) into space.
It's about one-tenth the number of Sesame Seeds on a Big Mac bun
The count of Sesame Seeds on a Big Mac bun is about 350.
(McDonald's sandwich; approximate figures)
Each McDonald's Big Mac crown bun contains about 350 sesame seeds. McDonald's serves about 1.57 million Big Macs to its customers each day.
It's about ten times the number of Living U.S. Presidents

The count of Living U.S. Presidents is about 4.
(a.k.a. Presidents of the United States; a.k.a. Presidents of the United States of America; a.k.a. POTUS), (2016 figures) (including current)
It's about one-tenth the number of Stores in the Mall of America

The count of Stores in the Mall of America is about 520.
(a.k.a. MOA, a.k.a. MoA, a.k.a. Megamall) (Bloomington, Minnesota) (2015 figures) (approximate)
Minnesota's Mall of America is home to 520 stores and attractions, including a wedding chapel, aquarium, and amusement park. Each year, an estimated 42 million people visit The Mall.
It's about one-fifteenth the number of Members of Parliament (The U.K.)

The count of Members of Parliament (The U.K.) is about 650.
(a.k.a. MPs) (2016 figures) (formally "Members of the House of Commons of the Parliament of the United Kingdom of Great Britain and Northern Ireland")
It's about one-fifteenth the number of Inductees in the Rock and Roll Hall of Fame
The count of Inductees in the Rock and Roll Hall of Fame is about 749.
(November, 2015 figures) (including individuals and groups)
It's about one-fifteenth the number of Kernels on an Ear of Corn
The count of Kernels on an Ear of Corn is about 800.
(Corn, a.k.a. Maize; Kernel a.k.a. Seed) (average) (for Dent Corn, a.k.a. field corn)
It's about one-twentieth the number of Population of Vatican City

The count of Population of Vatican City is about 842.
(a.k.a. Vatican City State, a.k.a. Stato della Città del Vaticano, a.k.a. Status Civitatis Vaticanae) (Rome, Italy) (2014 estimates; permanent residents only)
Vatican City, the seat of the Roman Catholic Church, is the smallest internationally recognized state in the world, with a population of just 842 people (according to a 2004 estimate). Each year, approximately 18 million tourists visit The City.
It's about twenty times the number of Escalators in the State of Wyoming

The count of Escalators in the State of Wyoming is about 2.
(2013 figures)
There are only two escalators in the State of Wyoming (although there are apparently plenty of elevators). It is speculated that the lack of escalators is due to the older age of the buildings and the abundance of cheap land resulting in single-story structures. At the time the last count of escalators was made, the state had a population of just 576,000 people.
It's about one-thirty-fifth the number of Golf Courses in Florida

The count of Golf Courses in Florida is about 1,518.
(2016 figures) (public and private)
It's about one-forty-fifth the number of Steps in the Sears Tower

The count of Steps in the Sears Tower is about 2,109.
(a.k.a. Willis Tower) (Chicago, Illinois) (steps per stairwell)
The Sears Tower extends 108 stories into the sky above the city of Chicago and includes 2,109 steps in each of its stairwells. Each year, more than 1.3 million visitors make the trip to an observation area called the Skydeck on the 103rd floor.
It's about one-forty-fifth the number of Daily Newspapers in Circulation Worldwide
The count of Daily Newspapers in Circulation Worldwide is about 2,111.
(2013 figures) (regional and local, plus national figures; paid only)
There are 2,111 paid, daily newspapers with a regional, local, or national distribution in circulation worldwide. Combined, these newspapers have a readership of about 150 million people.
It's about one-one-hundredth the number of Bishops in the Catholic Church
The count of Bishops in the Catholic Church is about 5,352.
(2015 figures; total Latin and Eastern Church figures; including Pope)